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1. Velocity independent constraints on spin-dependent DM-nucleon interactions from IceCube and PICO

Author: M. G. Aartsen, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, C. Alispach, K. Andeen, T. Anderson, I. Ansseau, G. Anton, C. Argüelles, J. Auffenberg, S. Axani, P. Backes, H. Bagherpour, X. Bai, A. Balagopal V., A. Barbano, S. W. Barwick, B. Bastian, V. Baum, S. Baur, R. Bay, J. J. Beatty, K.-H. Becker, J. Becker Tjus, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, D. Bindig, E. Blaufuss, S. Blot, C. Bohm, M. Börner, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, J. Bourbeau, F. Bradascio, J. Braun, S. Bron, J. Brostean-Kaiser, A. Burgman, J. Buscher, R. S. Busse, T. Carver, C. Chen, E. Cheung, D. Chirkin, S. Choi, L. Classen, A. Coleman, G. H. Collin, J. M. Conrad, P. Coppin, P. Correa, D. F. Cowen, R. Cross, P. Dave, C. De Clercq, J. J. DeLaunay, H. Dembinski, K. Deoskar, S. De Ridder, P. Desiati, K. D. de Vries, G. de Wasseige, M. de With, T. DeYoung, A. Diaz, J. C. Díaz-Vélez, H. Dujmovic, M. Dunkman, E. Dvorak, B. Eberhardt, T. Ehrhardt, P. Eller, R. Engel, P. A. Evenson, S. Fahey, A. R. Fazely, J. Felde, K. Filimonov, C. Finley, A. Franckowiak, E. Friedman, A. Fritz, T. K. Gaisser, J. Gallagher, E. Ganster, S. Garrappa, L. Gerhardt, K. Ghorbani, T. Glauch, T. Glüsenkamp, A. Goldschmidt, J. G. Gonzalez, D. Grant, Z. Griffith, S. Griswold, M. Günder, M. Gündüz, C. Haack, A. Hallgren, L. Halve, F. Halzen, K. Hanson, A. Haungs, D. Hebecker, D. Heereman, P. Heix, K. Helbing, R. Hellauer, F. Henningsen, S. Hickford, J. Hignight, G. C. Hill, K. D. Hoffman, R. Hoffmann, T. Hoinka, B. Hokanson-Fasig, K. Hoshina, F. Huang, M. Huber, T. Huber, K. Hultqvist, M. Hünnefeld, R. Hussain, S. In, N. Iovine, A. Ishihara, G. S. Japaridze, M. Jeong, K. Jero, B. J. P. Jones, F. Jonske, R. Joppe, D. Kang, W. Kang, A. Kappes, D. Kappesser, T. Karg, M. Karl, A. Karle, U. Katz, M. Kauer, J. L. Kelley, A. Kheirandish, J. Kim, T. Kintscher, J. Kiryluk, T. Kittler, S. R. Klein, R. Koirala, H. Kolanoski, L. Köpke, C. Kopper, S. Kopper, D. J. Koskinen, M. Kowalski, K. Krings, G. Krückl, N. Kulacz, N. Kurahashi, A. Kyriacou, M. Labare, J. L. Lanfranchi, M. J. Larson, F. Lauber, J. P. Lazar, K. Leonard, A. Leszczynska, M. Leuermann, Q. R. Liu, E. Lohfink, C. J. Lozano Mariscal, L. Lu, F. Lucarelli, J. Lünemann, W. Luszczak, Y. Lyu, W. Y. Ma, J. Madsen, G. Maggi, K. B. M. Mahn, Y. Makino, P. Mallik, K. Mallot, S. Mancina, I. C. Mariş, R. Maruyama, K. Mase, R. Maunu, F. McNally, K. Meagher, M. Medici, A. Medina, M. Meier, S. Meighen-Berger, T. Menne, G. Merino, T. Meures, J. Micallef, G. Momenté, T. Montaruli, R. W. Moore, R. Morse, M. Moulai, P. Muth, R. Nagai, U. Naumann, G. Neer, H. Niederhausen, S. C. Nowicki, D. R. Nygren, A. Obertacke Pollmann, M. Oehler, A. Olivas, A. O’Murchadha, E. O’Sullivan, T. Palczewski, H. Pandya, D. V. Pankova, N. Park, P. Peiffer, C. Pérez de los Heros, S. Philippen, D. Pieloth, E. Pinat, A. Pizzuto, M. Plum, A. Porcelli, P. B. Price, G. T. Przybylski, C. Raab, A. Raissi, M. Rameez, L. Rauch, K. Rawlins, I. C. Rea, R. Reimann, B. Relethford, M. Renschler, G. Renzi, E. Resconi, W. Rhode, M. Richman, S. Robertson, M. Rongen, C. Rott, T. Ruhe, D. Ryckbosch, D. Rysewyk, I. Safa, S. E. Sanchez Herrera, A. Sandrock, J. Sandroos, M. Santander, S. Sarkar, K. Satalecka, M. Schaufel, H. Schieler, P. Schlunder, T. Schmidt, A. Schneider, J. Schneider, F. G. Schröder, L. Schumacher, S. Sclafani, D. Seckel, S. Seunarine, S. Shefali, M. Silva, R. Snihur, J. Soedingrekso, D. Soldin, M. Song, G. M. Spiczak, C. Spiering, J. Stachurska, M. Stamatikos, T. Stanev, R. Stein, P. Steinmüller, J. Stettner, A. Steuer, T. Stezelberger, R. G. Stokstad, A. Stössl, N. L. Strotjohann, T. Stürwald, T. Stuttard, G. W. Sullivan, I. Taboada, F. Tenholt, S. Ter-Antonyan, A. Terliuk, S. Tilav, L. Tomankova, C. Tönnis, S. Toscano, D. Tosi, A. Trettin, M. Tselengidou, C. F. Tung, A. Turcati, R. Turcotte, C. F. Turley, B. Ty, E. Unger, M. A. Unland Elorrieta, M. Usner, J. Vandenbroucke, W. Van Driessche, D. van Eijk, N. van Eijndhoven, S. Vanheule, J. van Santen, M. Vraeghe, C. Walck, A. Wallace, M. Wallraff, N. Wandkowsky, T. B. Watson, C. Weaver, A. Weindl, M. J. Weiss, J. Weldert, C. Wendt, J. Werthebach, B. J. Whelan, N. Whitehorn, K. Wiebe, C. H. Wiebusch, L. Wille, D. R. Williams, L. Wills, M. Wolf, J. Wood, T. R. Wood, K. Woschnagg, G. Wrede, D. L. Xu, X. W. Xu, Y. Xu, J. P. Yanez, G. Yodh, S. Yoshida, T. Yuan, M. Zöcklein, IceCube Collaboration, C. Amole, M. Ardid, I. J. Arnquist, D. M. Asner, D. Baxter, E. Behnke, M. Bressler, B. Broerman, G. Cao, C. J. Chen, U. Chowdhury, K. Clark, J. I. Collar, P. S. Cooper, M. Crisler, G. Crowder, N. A. Cruz-Venegas, C. E. Dahl, M. Das, S. Fallows, J. Farine, I. Felis, R. Filgas, F. Girard, G. Giroux, J. Hall, C. Hardy, O. Harris, E. W. Hoppe, M. Jin, L. Klopfenstein, C. B. Krauss, M. Laurin, I. Lawson, A. Leblanc, I. Levine, W. H. Lippincott, F. Mamedov, D. Maurya, P. Mitra, C. Moore, T. Nania, R. Neilson, A. J. Noble, P. Oedekerk, A. Ortega, M.-C. Piro, A. Plante, R. Podviyanuk, S. Priya, A. E. Robinson, S. Sahoo, O. Scallon, S. Seth, A. Sonnenschein, N. Starinski, I. Štekl, T. Sullivan, F. Tardif, E. Vázquez-Jáuregui, N. Walkowski, U. Wichoski, Y. Yan, V. Zacek, J. Zhang, and PICO Collaboration
Subjects: Astrophysics, QB460-466, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract: Abstract Adopting the Standard Halo Model (SHM) of an isotropic Maxwellian velocity distribution for dark matter (DM) particles in the Galaxy, the most stringent current constraints on their spin-dependent scattering cross-section with nucleons come from the IceCube neutrino observatory and the PICO-60 $$\hbox {C}_3\hbox {F}_8$$ C 3 F 8 superheated bubble chamber experiments. The former is sensitive to high energy neutrinos from the self-annihilation of DM particles captured in the Sun, while the latter looks for nuclear recoil events from DM scattering off nucleons. Although slower DM particles are more likely to be captured by the Sun, the faster ones are more likely to be detected by PICO. Recent N-body simulations suggest significant deviations from the SHM for the smooth halo component of the DM, while observations hint at a dominant fraction of the local DM being in substructures. We use the method of Ferrer et al. (JCAP 1509: 052, 2015) to exploit the complementarity between the two approaches and derive conservative constraints on DM-nucleon scattering. Our results constrain $$\sigma _{\mathrm{SD}} \lesssim 3 \times 10^{-39} \mathrm {cm}^2$$ σ SD ≲ 3 × 10 - 39 cm 2 ( $$6 \times 10^{-38} \mathrm {cm}^2$$ 6 × 10 - 38 cm 2 ) at $$\gtrsim 90\%$$ ≳ 90 % C.L. for a DM particle of mass 1 TeV annihilating into $$\tau ^+ \tau ^-$$ τ + τ - ( $$b\bar{b}$$ b b ¯ ) with a local density of $$\rho _{\mathrm{DM}} = 0.3~\mathrm {GeV/cm}^3$$ ρ DM = 0.3 GeV / cm 3 . The constraints scale inversely with $$\rho _{\mathrm{DM}}$$ ρ DM and are independent of the DM velocity distribution.
Published: 2020
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2. Final results of the PICASSO dark matter search experiment

Author: X. Dai, C. M. Jackson, P. Mitra, M. Fines-Neuschild, U. Wichoski, I. T. Lawson, A. Kamaha, R. Podviyanuk, C. B. Krauss, S. Seth, F. Debris, L. Lessard, N. Dhungana, J. P. Martin, E. Grace, O. Scallon, I. Stekl, M. Lafrenière, Mala Das, Ilan Levine, N. Starinski, E. Behnke, S. Gagnebin, D. Marlisov, A. Davour, J. Farine, A. J. Noble, Stanislav Pospisil, Pijushpani Bhattacharjee, M. Besnier, M. Laurin, A. Plante, V. Zacek, and G. Giroux
Subjects: Physics, Particle physics, Complete data, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Physics - Instrumentation and Detectors, 010308 nuclear & particles physics, Dark matter, Detector, Bubble nucleation, FOS: Physical sciences, Astronomy and Astrophysics, Instrumentation and Detectors (physics.ins-det), 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), WIMP, 0103 physical sciences, PICASSO, 010306 general physics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The PICASSO dark matter search experiment operated an array of 32 superheated droplet detectors containing 3.0 kg of C$_{4}$F$_{10}$ and collected an exposure of 231.4 kgd at SNOLAB between March 2012 and January 2014. We report on the final results of this experiment which includes for the first time the complete data set and improved analysis techniques including \mbox{acoustic} localization to allow fiducialization and removal of higher activity regions within the detectors. No signal consistent with dark matter was observed. We set limits for spin-dependent interactions on protons of $\sigma_p^{SD}$~=~1.32~$\times$~10$^{-2}$~pb (90\%~C.L.) at a WIMP mass of 20 GeV/c$^{2}$. In the spin-independent sector we exclude cross sections larger than $\sigma_p^{SI}$~=~4.86~$\times$~10$^{-5 }$~pb~(90\% C.L.) in the region around 7 GeV/c$^{2}$. The pioneering efforts of the PICASSO experiment have paved the way forward for a next generation detector incorporating much of this technology and experience into larger mass bubble chambers., Comment: 24 pages, 7 figures
Published: 2017

3. Data-driven modeling of electron recoil nucleation in PICO C3F8 bubble chambers

Author: Mala Das, T. Nania, E. Behnke, L. Klopfenstein, S. Fallows, D. Tiwari, A. Plante, W. H. Lippincott, C. E. Dahl, A. Hagen, D. M. Asner, S. Sahoo, Jie Zhang, C. Licciardi, C. B. Coutu, B. Loer, M. Ardid, D. Baxter, C. B. Krauss, J. Fuentes, S. Pal, C. M. Jackson, F. Tardif, Ilan Levine, N. A. Cruz-Venegas, J. I. Collar, Satyajit Seth, Shashank Priya, K. Wierman, A. Leblanc, G. Cao, U. Chowdhury, F. Mamedov, T. Sullivan, R. Neilson, M.-C. Piro, N. Walkowski, W. Woodley, P. S. Cooper, R. Filgas, E. Weima, Amber M. Ortega, G. Crowder, O. Harris, C. Amole, T. Kozynets, S. Chen, G. Giroux, E. Vázquez-Jáuregui, P. Mitra, M. Jin, J. M. Wagner, P. Oedekerk, N. Starinski, A. Sonnenschein, B. Broerman, C. Cowles, O. Scallon, B. Hackett, A. E. Robinson, M. B. Crisler, I. J. Arnquist, F. Girard, U. Wichoski, T. Hillier, Yongke Yan, I. Stekl, Chujie Chen, C. Hardy, M. Bressler, C. D. Moore, J. Hall, J. Farine, Karl J. Clark, I. Lawson, A. J. Noble, M. Laurin, V. Zacek, and Eric W. Hoppe
Subjects: Physics, 010308 nuclear & particles physics, Endowment, Atomic energy, European Regional Development Fund, Library science, 7. Clean energy, 01 natural sciences, Mine site, 0103 physical sciences, Christian ministry, 010306 general physics, Engineering research, National laboratory, Underground space
Abstract: The PICO Collaboration wishes to thank SNOLAB and its staff for support through underground space, logistical and technical services. SNOLAB operations are supported by the Canada Foundation for Innovation and the Province of Ontario Ministry of Research and Innovation, with underground access provided by Vale at the Creighton mine site. We wish to acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI) for funding. We acknowledge the support from National Science Foundation (NSF) (Grants No. 0919526, No. 1506337, No. 1242637, No. 1205987, and No. 1806722). We acknowledge that this work is supported by the U.S. Department of Energy (DOE) Office of Science, Office of High Energy Physics (under Award No. DE-SC-0012161), by DGAPA-UNAM (PAPIIT No. IA100118) and Consejo Nacional de Ciencia y Tecnologia (CONACyT, M?exico, Grants No. 252167 and No. A1-S-8960), by the Department of Atomic Energy (DAE), Government of India, under the Centre for AstroParticle Physics II project (CAPP-II) at the Saha Institute of Nuclear Physics (SINP), European Regional Development Fund?Project ?Engineering Applications of Microworld Physics? (Project No. CZ.02.1.01/0.0/0.0/ 16_019/0000766), and the Spanish Ministerio de Ciencia, Innovacion y Universidades (Red Consolider MultiDark, Grant No. FPA2017-90566-REDC). This work is partially supported by the Kavli Institute for Cosmological Physics at the University of Chicago through NSF Grant No. 1125897, and an endowment from the Kavli Foundation and its founder Fred Kavli. We also wish to acknowledge the support from Fermi National Accelerator Laboratory under Contract No. DE-AC02-07CH11359, and Pacific Northwest National Laboratory, which is operated by Battelle for the U.S. Department of Energy under Contract No. DE-AC05- 76RL01830. We also thank Compute Canada [75] and the Center for Advanced Computing, ACENET, Calcul Qu?ebec, Compute Ontario, and WestGrid for computational support.
Published: 2019

4. Dark matter search results from the complete exposure of the PICO-60 C3F8 bubble chamber

Author: W. H. Lippincott, J. Hall, O. Harris, E. Behnke, C. B. Coutu, Chujie Chen, M. Jin, T. Sullivan, U. Chowdhury, F. Girard, Ivan Felis, C. Hardy, O. Scallon, C. M. Jackson, J. Farine, G. Cao, F. Mamedov, R. Filgas, R. Neilson, M. Bressler, A. Leblanc, T. Nania, S. Fallows, P. S. Cooper, N. Starinski, E. Weima, Ilan Levine, N. A. Cruz-Venegas, C. D. Moore, M.-C. Piro, F. Tardif, E. Vázquez-Jáuregui, Eric W. Hoppe, G. Crowder, C. Amole, B. Broerman, Shashank Priya, G. Giroux, Jie Zhang, K. Wierman, C. B. Krauss, A. Plante, M. Laurin, B. Loer, Amber M. Ortega, T. Hillier, D. M. Asner, V. Zacek, C. Licciardi, C. Cowles, S. Sahoo, L. Klopfenstein, A. E. Robinson, Karl J. Clark, N. Walkowski, Satyajit Seth, Yongke Yan, I. Stekl, I. Lawson, A. Sonnenschein, J. I. Collar, A. J. Noble, M. B. Crisler, I. J. Arnquist, U. Wichoski, C. E. Dahl, T. Kozynets, R. Podviyanuk, M. Ardid, D. Baxter, P. Mitra, P. Oedekerk, and Mala Das
Subjects: Physics, 010308 nuclear & particles physics, Endowment, Atomic energy, Library science, 01 natural sciences, Mine site, Regional development, 0103 physical sciences, Christian ministry, 010306 general physics, National laboratory, Engineering research, Underground space
Abstract: The PICO Collaboration wishes to thank SNOLAB and its staff for support through underground space, logistical and technical services. SNOLAB operations are supported by the Canada Foundation for Innovation and the Province of Ontario Ministry of Research and Innovation, with underground access provided by Vale at the Creighton mine site. We are grateful to Genevieve Belanger and Alexander Pukhov of the Universit e de Savoie for their useful correspondence regarding the interpretation of PICO results. We wish to acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI) for funding. We acknowledge the support from the National Science Foundation (NSF) (Grants No. 0919526, No. 1506337, No. 1242637, No. 1205987, and No. 1806722). We acknowledge that this work is supported by the U.S. Department of Energy (DOE) Office of Science, Office of High Energy Physics (under Award No. DE-SC-0012161), by the DOE Office of Science Graduate Student Research (SCGSR) award, by DGAPA-UNAM (PAPIIT No. IA100118) and Consejo Nacional de Ciencia y Tecnologia (CONACyT, Mexico, Grants No. 252167 and No. A1-S-8960), by the Department of Atomic Energy (DAE), Government of India, under the Centre for AstroParticle Physics II project (CAPP-II) at the Saha Institute of Nuclear Physics (SINP), European Regional Development FundProject "Engineering applications of microworld physics" (No. CZ. 02.1.01/0.0/0.0/16_019/0000766), and the Spanish (Ministry of Science, Innovation and Universities) Ministerio de Ciencia, Innovacion y Universidades (Red Consolider MultiDark, FPA2017-90566-REDC). This work is partially supported by the Kavli Institute for Cosmological Physics at the University of Chicago through NSF Grant No. 1125897, and an endowment from the Kavli Foundation and its founder Fred Kavli. We also wish to acknowledge the support from Fermi National Accelerator Laboratory under Contract No. DE-AC02-07CH11359, and from Pacific Northwest National Laboratory, which is operated by Battelle for the U.S. Department of Energy under Contract No. DE-AC05-76RL01830. We also thank Compute Canada (www.computecanada.ca) and the Centre for Advanced Computing, ACENET, Calcul Quebec, Compute Ontario and WestGrid for computational support.
Published: 2019

5. Searching for Dark Matter with PICASSO

Author: P. Mitra, Stanislav Pospisil, Pijushpani Bhattacharjee, I. Levine, S. Gagnebin, U. Wichoski, I. Stekl, M. Besnier, S. Archambault, C. B. Krauss, F. Debris, I. T. Lawson, N. Dhungana, A. Davour, G. Giroux, A. Kamaha, S. Seth, O. Scallon, E. Behnke, E. Grace, L. Lessard, D. Marlisov, M.-C. Piro, Mala Das, M. Lafrenière, C. M. Jackson, M. Laurin, V. Zacek, C. Levy, S. Kumaratunga, J. P. Martin, N. Starinski, J. Farine, T. Xie, A. Plante, A. J. Noble, R. Podviyanuk, X. Dai, and M. Fines-Neuschild
Subjects: Physics, Particle physics, Physics::Instrumentation and Detectors, Dark matter, Massive particle, PICASSO, Electron, SNOLAB, Physics and Astronomy(all), WIMPs, Nuclear physics, Superheated Liquids, WIMP, Weakly interacting massive particles, Dark Matter, Bubble chamber, Particle
Abstract: The Project In CAnada to Search for Supersymmetric Objects (PICASSO) at SNOLAB searches for Weakly Interacting Massive Particle (WIMP) interactions with 19 F. It is particularly sensitive to spin-dependent particle interactions. It uses a droplet technique, based on the principle of a bubble chamber, in which phase transitions in superheated liquids can be triggered by WIMP induced nuclear recoils. The detection process allows a highly e ffi cient suppression of backgrounds from cosmic muons, γ rays and electrons. Recent results and progress are presented and future plans to scale this technique to large masses with the PICO collaboration are briefly discussed.
Published: 2015

6. Dark Matter Search Results from the PICO−60 C3F8 Bubble Chamber

Author: T. Nania, M. Laurin, U. Chowdhury, G. Giroux, V. Zacek, Amber M. Ortega, O. Scallon, Eric W. Hoppe, W. H. Lippincott, J. Hall, M. Ardid, D. Baxter, G. Cao, P. Campion, J. Farine, Yongke Yan, I. Stekl, F. Mamedov, Satyajit Seth, A. E. Robinson, Deepam Maurya, A. Roeder, Jie Zhang, F. Tardif, P. S. Cooper, C. B. Krauss, S. Olson, Shashank Priya, H. Borsodi, F. Girard, C. E. Dahl, Ilan Levine, E. Vázquez-Jáuregui, J. I. Collar, R. Podviyanuk, O. Harris, J. Wells, R. Rucinski, Ivan Felis, R. Filgas, Manuel Bou-Cabo, G. Crowder, R. Neilson, C. Amole, N. Starinski, M. Jin, Karl J. Clark, Chujie Chen, I. Lawson, A. J. Noble, S. Fallows, A. Plante, D. M. Asner, Mala Das, Pijushpani Bhattacharjee, M. B. Crisler, I. J. Arnquist, U. Wichoski, P. Mitra, A. Sonnenschein, A. Leblanc, and E. Behnke
Subjects: 010308 nuclear & particles physics, Endowment, Atomic energy, 0103 physical sciences, General Physics and Astronomy, Library science, Christian ministry, 010306 general physics, National laboratory, Student research, 01 natural sciences, Mine site, Underground space
Abstract: The PICO Collaboration wishes to thank SNOLAB and its staff for support through underground space, logistical, and technical services. SNOLAB operations are supported by the Canada Foundation for Innovation and the Province of Ontario Ministry of Research and Innovation, with underground access provided by Vale at the Creighton mine site. We are grateful to Kristian Hahn and Stanislava Sevova of Northwestern University and Bjorn Penning of the University of Bristol for their assistance and useful discussion. We wish to acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Canada Foundation for Innovation (CFI) for funding. We acknowledge the support from National Science Foundation (NSF) (Grants No. 0919526, No. 1506337, No. 1242637, and No. 1205987). We acknowledge that this work is supported by the U.S. Department of Energy (DOE) Office of Science, Office of High Energy Physics (under Award No. DE-SC-0012161), by a DOE Office of Science Graduate Student Research (SCGSR) award, by Direccion General Asuntos del Personal Academico, Universidad Nacional Autonoma de Mexico (DGAPA-UNAM) through the grant Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT) No. IA100316 and by Consejo Nacional de Ciencia y Tecnologia (CONACyT) (Mexico) through Grant No. 252167, by the Department of Atomic Energy (DAE), the Government of India, under the Center of AstroParticle Physics II project (CAPP-II) at Saha Institute of Nuclear Physics (SINP), by the Czech Ministry of Education, Youth and Sports (Grant No. LM2015072), and by the Spanish Ministerio de Economia y Competitividad, Consolider MultiDark (Grant No. CSD2009-00064). This work is partially supported by the Kavli Institute for Cosmological Physics at the University of Chicago through NSF Grant No. 1125897, and an endowment from the Kavli Foundation and its founder Fred Kavli. We also wish to acknowledge the support from Fermi National Accelerator Laboratory under Contract No. De-AC02-07CH11359, and Pacific Northwest National Laboratory, which is operated by Battelle for the U.S. Department of Energy under Contract No. DE-AC05-76RL01830. We also thank Compute Canada and the Center for Advanced Computing, ACENET, Calcul Quebec, Compute Ontario, and WestGrid for the computational support.
Published: 2017

7. Dark Matter Search Results from the PICO-60 C$_3$F$_8$ Bubble Chamber

Author: C, Amole, M, Ardid, I J, Arnquist, D M, Asner, D, Baxter, E, Behnke, P, Bhattacharjee, H, Borsodi, M, Bou-Cabo, P, Campion, G, Cao, C J, Chen, U, Chowdhury, K, Clark, J I, Collar, P S, Cooper, M, Crisler, G, Crowder, C E, Dahl, M, Das, S, Fallows, J, Farine, I, Felis, R, Filgas, F, Girard, G, Giroux, J, Hall, O, Harris, E W, Hoppe, M, Jin, C B, Krauss, M, Laurin, I, Lawson, A, Leblanc, I, Levine, W H, Lippincott, F, Mamedov, D, Maurya, P, Mitra, T, Nania, R, Neilson, A J, Noble, S, Olson, A, Ortega, A, Plante, R, Podviyanuk, S, Priya, A E, Robinson, A, Roeder, R, Rucinski, O, Scallon, S, Seth, A, Sonnenschein, N, Starinski, I, Štekl, F, Tardif, E, Vázquez-Jáuregui, J, Wells, U, Wichoski, Y, Yan, V, Zacek, and J, Zhang
Subjects: High Energy Physics - Experiment (hep-ex), Physics - Instrumentation and Detectors, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Physics::Instrumentation and Detectors, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Experiment
Abstract: New results are reported from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 52 kg of C$_3$F$_8$ located in the SNOLAB underground laboratory. As in previous PICO bubble chambers, PICO-60 C$_3$F$_8$ exhibits excellent electron recoil and alpha decay rejection, and the observed multiple-scattering neutron rate indicates a single-scatter neutron background of less than 1 event per month. A blind analysis of an efficiency-corrected 1167-kg-day exposure at a 3.3-keV thermodynamic threshold reveals no single-scattering nuclear recoil candidates, consistent with the predicted background. These results set the most stringent direct-detection constraint to date on the WIMP-proton spin-dependent cross section at 3.4 $\times$ 10$^{-41}$ cm$^2$ for a 30-GeV$\thinspace$c$^{-2}$ WIMP, more than one order of magnitude improvement from previous PICO results., Comment: 6 pages, 6 figures
Published: 2017
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8. Improved dark matter search results from PICO-2L Run 2

Author: J. Farine, A. J. Noble, M. Laurin, M. Ruschman, V. Zacek, W. H. Lippincott, J. Hall, Jie Zhang, C. B. Krauss, F. Girard, Deepam Maurya, J. Wells, J. I. Collar, C. M. Jackson, K. Clark, D. Baxter, I. Levine, M. Jin, A. E. Robinson, Eric W. Hoppe, R. B. Podviianiuk, Daniel Broemmelsiek, A. Leblanc, C. Amole, F. Debris, S. J. Brice, G. Giroux, Miguel Ardid, S. Fallows, R. Neilson, I. Lawson, E. Mann, H. Borsodi, M. B. Crisler, I. J. Arnquist, U. Wichoski, S. Olson, D. M. Asner, O. Scallon, Pijushpani Bhattacharjee, M. Fines-Neuschild, I. Stekl, Mala Das, J. P. Martin, Manuel Bou-Cabo, P. Mitra, Shashank Priya, E. Behnke, Ivan Felis, R. Filgas, A. Plante, N. Starinski, P. S. Cooper, E. Vázquez-Jáuregui, Andrew Sonnenschein, M. Lafrenière, O. Harris, and C. E. Dahl
Subjects: Physics, Particle physics, Physics - Instrumentation and Detectors, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Atomic energy, FOS: Physical sciences, Library science, Instrumentation and Detectors (physics.ins-det), 01 natural sciences, 7. Clean energy, Technical support, FISICA APLICADA, 0103 physical sciences, Christian ministry, 010306 general physics, National laboratory, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: New data are reported from a second run of the 2-liter PICO-2L C3F8 bubble chamber with a total exposure of 129 kg-days at a thermodynamic threshold energy of 3.3 keV. These data show that measures taken to control particulate contamination in the superheated fluid resulted in the absence of the anomalous background events observed in the first run of this bubble chamber. One single nuclear-recoil event was observed in the data, consistent both with the predicted background rate from neutrons and with the observed rate of unambiguous multiple-bubble neutron scattering events. The chamber exhibits the same excellent electron-recoil and alpha decay rejection as was previously reported. These data provide the most stringent direct detection constraints on weakly interacting massive particle (WIMP)-proton spin-dependent scattering to date for WIMP masses < 50 GeV/c(2)., The PICO Collaboration thanks SNOLAB for their exceptional laboratory space and technical support. We also thank Fermi National Accelerator Laboratory (Contract No. DE-AC02-07CH11359) and Pacific Northwest National Laboratory for their support. This work is supported by the National Sciences and Engineering Research Council of Canada (NSERC), the Canada Foundation for Innovation (CFI), the National Science Foundation (NSF) under the Grants No. PHY-1242637, No. PHY-0919526, No. PHY-1205987, and No. PHY-1506377 and by the U.S. Department of Energy under Award No. DE-SC-0012161. We also acknowledge the support of Department of Atomic Energy (DAE), Government of India, under the Center of AstroParticle Physics II project (CAPP-II) at Saha Institute of Physics (SINP); the Czech Ministry of Education, Youth and Sports (Grant No. LM2011027); the Spanish Ministerio de Economia y Competitividad, Consolider MultiDark (Grant No. CSD2009-00064) and DGAPA-UNAM through grant PAPIIT No. IA100316.
Published: 2016

9. Angular analysis of the muon pair asymmetry at LEP 1

Author: G. Abbiendi, C. Ainsley, P.F. Åkesson, G. Alexander, J. Allison, G. Anagnostou, K.J. Anderson, S. Arcelli, S. Asai, D. Axen, G. Azuelos, I. Bailey, E. Barberio, R.J. Barlow, R.J. Batley, T. Behnke, K.W. Bell, P.J. Bell, G. Bella, A. Bellerive, S. Bethke, O. Biebel, I.J. Bloodworth, O. Boeriu, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, L. Brigliadori, R.M. Brown, H.J. Burckhart, J. Cammin, R.K. Carnegie, B. Caron, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, P.E.L. Clarke, E. Clay, I. Cohen, J. Couchman, A. Csilling, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, A. De Roeck, E.A. De Wolf, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, E. Etzion, F. Fabbri, L. Feld, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, D. Glenzinski, J. Goldberg, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, A. Gupta, C. Hajdu, M. Hamann, G.G. Hanson, K. Harder, A. Harel, M. Harin-Dirac, M. Hauschild, J. Hauschildt, C.M. Hawkes, R. Hawkings, R.J. Hemingway, C. Hensel, G. Herten, R.D. Heuer, J.C. Hill, K. Hoffman, R.J. Homer, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, K. Ishii, A. Jawahery, H. Jeremie, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, T.P. Kokott, S. Komamiya, R.V. Kowalewski, T. Krämer, T. Kress, P. Krieger, J. von Krogh, D. Krop, T. Kuhl, M. Kupper, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, I. Lawson, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, J. Lillich, C. Littlewood, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Lu, J. Ludwig, A. Macchiolo, A. Macpherson, W. Mader, S. Marcellini, T.E. Marchant, A.J. Martin, J.P. Martin, G. Martinez, G. Masetti, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, T.J. McMahon, R.A. McPherson, F. Meijers, P. Mendez-Lorenzo, W. Menges, F.S. Merritt, H. Mes, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, S. Moed, W. Mohr, T. Mori, A. Mutter, K. Nagai, I. Nakamura, H.A. Neal, R. Nisius, S.W. O'Neale, A. Oh, A. Okpara, M.J. Oreglia, S. Orito, C. Pahl, G. Pásztor, J.R. Pater, G.N. Patrick, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, O. Pooth, A. Quadt, K. Rabbertz, C. Rembser, P. Renkel, H. Rick, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, Y. Rozen, K. Runge, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, F. Spano, M. Sproston, A. Stahl, K. Stephens, D. Strom, R. Ströhmer, L. Stumpf, B. Surrow, S. Tarem, M. Tasevsky, R.J. Taylor, R. Teuscher, J. Thomas, M.A. Thomson, E. Torrence, D. Toya, T. Trefzger, A. Tricoli, I. Trigger, Z. Trócsányi, E. Tsur, M.F. Turner-Watson, I. Ueda, B. Ujvári, B. Vachon, C.F. Vollmer, P. Vannerem, M. Verzocchi, H. Voss, J. Vossebeld, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, V. Zacek, D. Zer-Zion, G., Abbiendi, C., Ainsley, P. F., Akesson, G., Alexander, J., Allison, G., Anagnostou, K. J., Anderson, S., Arcelli, S., Asai, D., Axen, G., Azuelo, I., Bailey, E., Barberio, R. J., Barlow, R. J., Batley, T., Behnke, K. W., Bell, P. J., Bell, G., Bella, A., Bellerive, S., Bethke, O., Biebel, I. J., Bloodworth, O., Boeriu, P., Bock, J., Bohme, D., Bonacorsi, M., Boutemeur, S., Braibant, L., Brigliador, R. M., Brown, H. J., Burckhart, J., Cammin, R. K., Carnegie, B., Caron, A. A., Carter, J. R., Carter, C. Y., Chang, D. G., Charlton, P. E., L., E., Clay, I., Cohen, J., Couchman, A., Csilling, M., Cuffiani, S., Dado, G. M., Dallavalle, S., Dallison, A., De Roeck, E. A., De, P., Dervan, K., Desch, B., Diene, M. S., Dixit, M., Donker, J., Dubbert, E., Duchovni, G., Duckeck, I. P., Duerdoth, E., Etzion, F., Fabbri, L., Feld, P., Ferrari, F., Fiedler, I., Fleck, M., Ford, A., Frey, A., Furtje, D. I., Futyan, P., Gagnon, J. W., Gary, G., Gaycken, C., Geich Gimbel, G., Giacomelli, P., Giacomelli, D., Glenzinski, J., Goldberg, K., Graham, E., Gro, J., Grunhau, M., Gruwe, P. O., Gunther, A., Gupta, C., Hajdu, M., Hamann, G. G., Hanson, K., Harder, A., Harel, M., Harin Dirac, M., Hauschild, J., Hauschildt, C. M., Hawke, R., Hawking, R. J., Hemingway, C., Hensel, G., Herten, R. D., Heuer, J. C., Hill, K., Hoffman, R. J., Homer, D., Horvath, K. R., Hossain, R., Howard, P., Huntemeyer, P., Igo Kemene, K., Ishii, A., Jawahery, H., Jeremie, C. R., Jone, P., Jovanovic, T. R., Junk, N., Kanaya, J., Kanzaki, G., Karapetian, D., Karlen, V., Kartvelishvili, K., Kawagoe, T., Kawamoto, R. K., Keeler, R. G., Kellogg, B. W., Kennedy, D. H., Kim, K., Klein, A., Klier, S., Kluth, T., Kobayashi, M., Kobel, T. P., Kokott, S., Komamiya, R. V., Kowalewski, T., Kramer, T., Kre, P., Krieger, J., van Krogh, D., Krop, T., Kuhl, M., Kupper, P., Kyberd, G. D., Lafferty, H., Landsman, D., Lanske, I., Lawson, J. G., Layter, A., Lein, D., Lellouch, J., Lett, L., Levinson, J., Lillich, C., Littlewood, S. L., Lloyd, F. K., Loebinger, G. D., Long, M. J., Losty, J., Lu, J., Ludwig, A., Macchiolo, A., Macpherson, W., Mader, S., Marcellini, T. E., Marchant, A. J., Martin, J. P., Martin, G., Martinez, G., Masetti, T., Mashimo, P., Mattig, W. J., Mcdonald, J., Mckenna, T. J., Mcmahon, R. A., Mcpherson, F., Meijer, P., Mendez Lorenzo, W., Menge, F. S., Merritt, H., Me, A., Michelini, S., Mihara, G., Mikenberg, D. J., Miller, S., Moed, W., Mohr, T., Mori, A., Mutter, K., Nagai, I., Nakamura, H. A., Neal, R., Nisiu, S. W., O'Neale, A., Oh, A., Okpara, M. J., Oreglia, S., Orito, C., Pahl, G., Pasztor, J. R., Pater, G. N., Patrick, J. E., Pilcher, J., Pinfold, D. E., Plane, B., Poli, J., Polok, O., Pooth, A., Quadt, K., Rabbertz, C., Rembser, P., Renkel, H., Rick, N., Rodning, J. M., Roney, S., Rosati, K., Roscoe, Y., Rozen, K., Runge, D. R., Rust, K., Sach, T., Saeki, O., Sahr, E. K., G., C., Sbarra, A. D., Schaile, O., Schaile, P., Scharff Hansen, M., Schroder, M., Schumacher, C., Schwick, W. G., Scott, R., Seuster, T. G., Shear, B. C., Shen, C. H., Shepherd Themistocleou, P., Sherwood, A., Skuja, A. M., Smith, G. A., Snow, R., Sobie, S., Soldner Rembold, Spagnolo, Stefania Antonia, F., Spano, M., Sproston, A., Stahl, K., Stephen, D., Strom, R., Strohmer, L., Stumpf, B., Surrow, S., Tarem, M., Tasevsky, R. J., Taylor, R., Teuscher, J., Thoma, M. A., Thomson, E., Torrence, D., Toya, T., Trefzger, A., Tricoli, I., Trigger, Z., Trocsanyi, E., Tsur, M. F., Turner Watson, I., Ueda, B., Ujvari, B., Vachon, C. F., Vollmer, P., Vannerem, M., Verzocchi, H., Vo, J., Vossebeld, D., Waller, C. P., Ward, D. R., Ward, P. M., Watkin, A. T., Watson, N. K., Watson, P. S., Well, T., Wengler, N., Werme, D., Wetterling, G. W., Wilson, J. A., Wilson, T. R., Wyatt, S., Yamashita, V., Zacek, D., Zer Zion, and OPAL Collaboration
Subjects: Physics, Particle physics, Nuclear and High Energy Physics, Muon, 010308 nuclear & particles physics, media_common.quotation_subject, Photon radiation, FOS: Physical sciences, Radiation, Interference (wave propagation), 01 natural sciences, Asymmetry, Standard Model, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Pair production, 0103 physical sciences, Invariant mass, High Energy Physics::Experiment, 010306 general physics, Particle Physics - Experiment, media_common
Abstract: Data on muon pair production obtained by the OPAL collaboration at centre of mass energies near the Z peak are analysed. Small angular mismatches between the directions of the two muons are used to assess the effects of initial state photon radiation and initial-final-state radiation interference on the forward-backward asymmetry of muon pairs. The dependence of the asymmetry on the invariant mass of the pair is measured in a model-independent way. Effective vector and axial-vector couplings of the Z boson are determined and compared to the Standard Model expectations., 31 pages, 8 figures, Accepted by Physics Letters B
Published: 2001
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10. Dark matter spin-dependent limits for WIMP interactions on 19F by PICASSO

Author: R. Gornea, M. Auger, I. Stekl, T. Shepherd, I. Levine, M. H. Genest, S. Kumaratunga, G. Giroux, Stanislav Pospisil, B. Beltran, Karl J. Clark, Claude Leroy, L. Lessard, F. Aubin, C. B. Krauss, P. Nadeau, A. Davour, U. Wichoski, C. Storey, C. Levy, E. Behnke, J. Farine, M.-C. Piro, A. J. Noble, S. Archambault, V. Zacek, N. Starinski, J. P. Martin, R. MacDonald, X. Dai, I. Lawson, and R. Faust
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Hadron, Dark matter, FOS: Physical sciences, Elementary particle, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, Baryon, High Energy Physics - Experiment (hep-ex), WIMP, 0103 physical sciences, Neutralino, Neutron, 010306 general physics, Nucleon
Abstract: The PICASSO experiment at SNOLAB reports new results for spin-dependent WIMP interactions on $^{19}$F using the superheated droplet technique. A new generation of detectors and new features which enable background discrimination via the rejection of non-particle induced events are described. First results are presented for a subset of two detectors with target masses of $^{19}$F of 65 g and 69 g respectively and a total exposure of 13.75 $\pm$ 0.48 kgd. No dark matter signal was found and for WIMP masses around 24 GeV/c$^2$ new limits have been obtained on the spin-dependent cross section on $^{19}$F of $\sigma_F$ = 13.9 pb (90% C.L.) which can be converted into cross section limits on protons and neutrons of $\sigma_p$ = 0.16 pb and $\sigma_n$ = 2.60 pb respectively (90% C.L). The obtained limits on protons restrict recent interpretations of the DAMA/LIBRA annual modulations in terms of spin-dependent interactions., Comment: Revised version, accepted for publication in Phys. Lett. B, 20 pages, 7 figures
Published: 2009

11. Status and Results of the PICASSO Experiment

Author: C. B. Krauss, Karl J. Clark, C. Storey, N. Van der Werf, U. Wichoski, M.-C. Piro, M. H. Genest, N. Starinsky, G. Giroux, Sabeshan Kanagalingam, L. Lessard, R. Gornea, J. Sodomka, W. Feighery, X. Dai, I. Stekl, Georges Azuelos, E. Behnke, M. Auger, F. Aubin, Stanislav Pospisil, J. P. Martin, Ilan Levine, Claude Leroy, R. Noulty, V. Zacek, and A. J. Noble
Subjects: Nuclear and High Energy Physics, media_common.quotation_subject, PICASSO, Art history, Art, Atomic and Molecular Physics, and Optics, media_common
Published: 2007

12. Dark Matter Search Results from the PICO-2LC3F8Bubble Chamber

Author: R. Neilson, M. Lafrenière, N. Starinski, C. M. Jackson, P. S. Cooper, E. Vázquez-Jáuregui, A. E. Robinson, J. P. Martin, J. I. Collar, M. Hai, M. Fines-Neuschild, S. Daley, M. Laurin, M. Ruschman, M. Jin, K. Clark, O. Harris, V. Zacek, U. Wichoski, D. Baxter, O. Scallon, Shashank Priya, Daniel Broemmelsiek, I. Levine, J. Hall, J. Wells, M. Bou-Cabo, Francoise Girard, J. Farine, G. Giroux, P. S. Bhattacharjee, A. Plante, C. Amole, R. B. Podviianiuk, Madhusmita Das, S. J. Brice, Andrew Sonnenschein, A. J. Noble, S. Seth, David M. Asner, Ivan Felis, R. Filgas, M. Crisler, E. Behnke, C. E. Dahl, F. Debris, Pitam Mitra, N. Dhungana, Miguel Ardid, E. Mann, I. Lawson, Jie Zhang, C. B. Krauss, W. H. Lippincott, Deepam Maurya, H. Borsodi, and I. Stekl
Subjects: Physics, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Dark matter, General Physics and Astronomy, 7. Clean energy, 01 natural sciences, Nuclear physics, Recoil, WIMP, Weakly interacting massive particles, DAMA/NaI, 0103 physical sciences, Bubble chamber, Neutron, Alpha decay, 010306 general physics
Abstract: New results are reported from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 52 kg of C_{3}F_{8} located in the SNOLAB underground laboratory. As in previous PICO bubble chambers, PICO-60 C_{3}F_{8} exhibits excellent electron recoil and alpha decay rejection, and the observed multiple-scattering neutron rate indicates a single-scatter neutron background of less than one event per month. A blind analysis of an efficiency-corrected 1167-kg day exposure at a 3.3-keV thermodynamic threshold reveals no single-scattering nuclear recoil candidates, consistent with the predicted background. These results set the most stringent direct-detection constraint to date on the weakly interacting massive particle (WIMP)-proton spin-dependent cross section at 3.4×10^{-41} cm^{2} for a 30-GeV c^{-2} WIMP, more than 1 order of magnitude improvement from previous PICO results.
Published: 2015

13. PICASSO, COUPP and PICO - search for dark matter with bubble chambers

Author: O. Harris, C. M. Jackson, I. Lawson, H. Borsodi, Ivan Felis, W. H. Lippincott, J. I. Collar, Deepam Maurya, A. Plante, A. E. Robinson, J. Zhang, M. Bou-Cabo, R. Filgas, G. Giroux, Ilan Levine, O. Scallon, K. Clark, Miguel Ardid, E. Behnke, M. Fines-Neuschild, C. E. Dahl, F. Debris, M. B. Crisler, C. B. Krauss, M. Hai, S. J. Brice, N. Dhungana, D. Baxter, Andrew Sonnenschein, Pijushpani Bhattacharjee, C. Amole, F. Girard, J. P. Martin, S. Seth, N. Starinski, J. Wells, Shashank Priya, U. Wichoski, E. Mann, R. Podviyanuk, P. Mitra, R. Neilson, Daniel Broemmelsiek, J. Hall, Mala Das, I. Stekl, D. M. Asner, J. Farine, A. J. Noble, M. Jin, M. Laurin, M. Ruschman, V. Zacek, P. S. Cooper, E. Vázquez-Jáuregui, and M. Lafrenière
Subjects: Physics, Nuclear physics, Range (particle radiation), Cold dark matter, Physics::Instrumentation and Detectors, Bubble, Weakly interacting massive particles, QC1-999, Dark matter, Underground laboratory, Bubble chamber, PICASSO
Abstract: The PICASSO and COUPP collaborations use superheated liquid detectors to search for cold dark matter through the direct detection of weakly interacting massive particles (WIMPs). These experiments, located in the underground laboratory of SNOLAB, Canada, detect phase transitions triggered by nuclear recoils in the keV range induced by interactions with WIMPs. We present details of the construction and operation of these detectors as well as the results, obtained by several years of observations. We also introduce PICO, a joint effort of the two collaborations to build a second generation ton-scale bubble chamber with 250 liters of active liquid.
Published: 2015

14. Direct dark matter search using large-mass superheated droplet detectors in the PICASSO experiment

Author: V. Zacek, A. J. Noble, Sabeshan Kanagalingam, M. Barnabé-Heider, M. Di Marco, Ilan Levine, Karl J. Clark, W. Feighery, Claude Leroy, S. N. Shore, R. Noulty, M. H. Genest, C. B. Krauss, Georges Azuelos, J. P. Martin, R. Guénette, U. Wichoski, P. Doane, E. Behnke, R. Gornea, and L. Lessard
Subjects: Hot Temperature, Large Underground Xenon experiment, Extraterrestrial Environment, Explosive material, Surface Properties, Physics::Instrumentation and Detectors, Dark matter, Cosmic ray, Astrophysics, Radiation Dosage, Sensitivity and Specificity, Particle detector, Nuclear physics, Recoil, Materials Testing, Radiology, Nuclear Medicine and imaging, Physics, Scintillation, Sudbury Neutrino Observatory, Microbubbles, Radiation, Radiological and Ultrasound Technology, Public Health, Environmental and Occupational Health, Reproducibility of Results, Dose-Response Relationship, Radiation, Equipment Design, General Medicine, Equipment Failure Analysis, Thermoluminescent Dosimetry, Gels, Cosmic Radiation
Abstract: The PICASSO experiment investigates the presence and nature of dark matter in the Universe. The experiment is based on the detection of acoustic signals generated in explosive phase transitions induced by dark matter particles. This technique is an alternative more traditional detection technique like scintillation and ionisation, which are largely employed for dark matter search. One of the main advantages of this technique, besides its sensitivity to very low nuclear recoil energies (few keV), is its excellent background suppression features. A pilot experiment consisting of six superheated droplet detectors (40 g of active mass) is presently taking data at the Sudbury Neutrino Observatory (SNO) at a depth of 2000 m. We discuss the operation, calibration and data acquisition of the experiment and also the ongoing work to increase the sensitivity and the active mass of the detectors.
Published: 2006

15. Search for heavy isosinglet neutrinos

Author: Baki Akkuş, S. Ricciardi, P. Stähelin, J. Panman, V. Zacek, T. Layda, Alexandre Rozanov, L. Gerland, G. Grégoire, U. Dore, A. Nathaniel, P. F. Loverre, T. Voss, F. W. Büsser, W. Lippich, A. Frenkel-Rambaldi, Ramazan Sever, H. Øverås, G. Rädel, V. Palladino, F. Marchetti-Stasi, R. Santacesaria, C. Foos, T. Mouthuy, K. Winter, M. Serin-Zeyrek, J. Vogt, E. Di Capua, R. Beyer, A. Maslennikov, D. De Pedis, K. Hiller, A. Capone, P. Strolin, G. Fiorillo, F. Niebergall, A. G. Cocco, W. Flegel, Pierre Vilain, P. Gorbunov, Denis Favart, G. Zacek, E. Knoops, H. Grote, A. Staude, E.A. Grigoriev, V. Khovansky, Antonio Ereditato, B. Saitta, R. Nahnhauer, E. Arik, Vincent Lemaitre, G. Piredda, S. Petrak, D. Macina, Gaston Wilquet, P. Tolun, H. E. Roloff, P., Vilain, G., Wilquet, S., Petrak, R., Beyer, W., Flegel, H., Grote, T., Mouthuy, H., Overa, J., Panman, K., Winter, G., Zacek, V., Zacek, F. W., Busser, C., Foo, L., Gerland, T., Layda, F., Niebergall, G., Radel, P., Stahelin, T., Vo, D., Favart, G., Gregoire, E., Knoop, V., Lemaitre, P., Gorbunov, E., Grigoriev, V., Khovansky, A., Maslennikov, A., Rozanov, W., Lippich, A., Nathaniel, A., Staude, J., Vogt, A. G., Cocco, A., Ereditato, Fiorillo, Giuliana, F., Marchettistasi, Palladino, Vittorio, P., Strolin, A., Capone, D., Depedi, U., Dore, A., Frenkelrambaldi, P. F., Loverre, D., Macina, G., Piredda, R., Santacesaria, E., Dicapua, S., Ricciardi, B., Saitta, B., Akku, E., Arik, M., Serinzeyrek, R., Sever, P., Tolun, K., Hiller, R., Nahnhauer, H. E., Roloff, Vilain, P., Wilquet, G., Petrak, S., Beyer, R., Flegel, W., Grote, H., Mouthuy, T., Øveras, H., Panman, J., Winter, K., Zacek, G., Zacek, V., Büsser, F. W., Foos, C., Gerland, L., Layda, T., Niebergall, F., Rädel, G., Stähelin, P., Voss, T., Favart, D., Grégoire, G., Knoops, E., Lemaître, V., Gorbunov, P., Grigoriev, E., Khovansky, V., Maslennikov, A., Rozanov, A., Lippich, W., Nathaniel, A., Staude, A., Vogt, J, Cocco, ALFREDO GIUSEPPE, Ereditato, A, Marchetti Stasi, F, Strolin, P, Capone, A, De Pedis, D, Dore, U, Frenkel Rambaldi, A, Loverre P., F, Macina, D, Piredda, G, Santacesaria, R, Di Capua, E, Ricciardi, S, Saitta, B, Akkus, B, Arik, E, Serin Zeyrek, M, Sever, R, Tolun, P, Hiller, K, Nahnhauer, R, and Roloff, H. E.
Subjects: Physics, Particle physics, Nuclear and High Energy Physics, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Solar neutrino, High Energy Physics::Phenomenology, Solar neutrino problem, Cosmic neutrino background, Nuclear physics, Neutrino detector, Measurements of neutrino speed, High Energy Physics::Experiment, Neutrino astronomy, Neutrino, Nuclear Experiment, Neutrino oscillation, Particle Physics - Experiment
Abstract: A new search for decays of heavy isosinglet neutrinos produced by neutral-current neutrino interactions in the CERN wide-band neutrino beam has been conducted by the CHARM-II Collaboration. We searched for heavy neutrinos created by scattering muon neutrinos on nucleons and decaying into μ + μ − ν μ . Production and decay of heavy neutrinos would appear as double events in the detector. Each double event candidate was tested wheather the measured quantities are compatible with the kinematics of this process. No event passed this test. The analysis is based on 2 × 10 7 neutral-current neutrino events collected from 1987–1991. The experiment is sensitive to heavy neutrinos in the mass range 0.3–2.4 GeV/ c 2 . The best limit for the mixing parameter is | U μi | 2 −5 for a mass around 2 GeV/ c 2 . The analysis improve order of magnitude previous results derived from wide-band neutrino beam exposures of the CHARM detector.
Published: 1995

16. Constraints on additional Z bosons derived from neutrino-electron scattering measurements

Author: J. Vogt, A. G. Cocco, D. De Pedis, P. Strolin, P. Gorbunov, Antonio Ereditato, H. E. Roloff, R. Beyer, Denis Favart, Ramazan Sever, T. Mouthuy, W. Flegel, R. Nahnhauer, H. Grote, Alexandre Rozanov, G. Rädel, G. Fiorillo, A. Staude, C. Foos, G. Zacek, E.A. Grigoriev, V. Khovansky, H. Øverås, D. Macina, E. Knoops, Vincent Lemaitre, K. Hiller, Gaston Wilquet, P. Tolun, Pierre Vilain, E. Di Capua, U. Dore, G. Piredda, B. Saitta, A. Capone, J. Panman, L. Gerland, A. Maslennikov, Baki Akkuş, T. Layda, A. Nathaniel, T. Voss, W. Lippich, A. Frenkel-Rambaldi, K. Winter, V. Palladino, R. Santacesaria, F. Marchetti-Stasi, E. Arik, G. Grégoire, P. F. Loverre, F. W. Büsser, S. Ricciardi, P. Stähelin, V. Zacek, M. Serin-Zeyrek, F. Niebergall, P., Vilain, G., Wilquet, R., Beyer, W., Flegel, H., Grote, T., Mouthuy, H., Overa, J., Panman, A., Rozanov, K., Winter, G., Zacek, V., Zacek, F. W., Busser, C., Foo, L., Gerland, T., Layda, F., Niebergall, G., Radel, P., Stahelin, T., Vo, D., Favart, G., Gregoire, E., Knoop, V., Lemaitre, P., Gorbunov, E., Grigoriev, V., Khovansky, A., Maslennikov, W., Lippich, A., Nathaniel, A., Staude, J., Vogt, A. G., Cocco, A., Ereditato, Fiorillo, Giuliana, F., Marchettistasi, Palladino, Vittorio, P., Strolin, A., Capone, D., Depedi, U., Dore, A., Frenkelrambaldi, P. F., Loverre, D., Macina, G., Piredda, R., Santacesaria, E., Dicapua, S., Ricciardi, B., Saitta, B., Akku, E., Arik, M., Serinzeyrek, R., Sever, P., Tolun, K., Hiller, R., Nahnhauer, and H. E., Roloff
Subjects: GAUGE BOSONS, Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Physics::Instrumentation and Detectors, Scattering, High Energy Physics::Phenomenology, Elementary particle, Supersymmetry, Nuclear physics, LIMITS, ELASTIC-SCATTERING, SEARCH, High Energy Physics::Experiment, VECTOR-BOSON, Charm (quantum number), Neutrino, MASSES, DETECTOR, Electron scattering, Particle Physics - Experiment, Boson
Abstract: We report new constraints on the existence of additional Z bosons derived from neutrino-electron scattering data. The analysis is based on data taken by the CHARM II Collaboration during five years of exposure of the detector to the wide band neutrino beam at CERN. The limits on the mass of these new particles are evaluated in the framework of E 6 superstring-inspired theories and Left-Right symmetric models. Limits on the so-called Z 1 are also reported.
Published: 1994

17. Performance of a new Micromegas detector, with woven wire mesh, in CF4

Author: A Geiser, Herbert Keppner, Patrick Jeanneret, V. Zacek, R. De Oliveira, J. Busto, and J.-L Vuilleumier
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, High energy particle, Electrode, Measuring instrument, Carbon–fluorine bond, Mechanical engineering, MicroMegas detector, Grid, Projection (set theory), Instrumentation, Particle detector
Abstract: Several techniques have been investigated to achieve good amplification in gas Time Projection Chambers. The classical Micromegas detection scheme with nickel grid is compared with a new one, with a stainless steel woven wire mesh, in CF4 at different operating pressures. The performances and the mechanical properties of the woven wire mesh make this solution attractive for low and high energy particle physics experiments and other applications like low dose radiography. A more detailed study appears in Jeanneret (Ph.D. Thesis, Neuchâtel University, 2001).
Published: 2003

18. Contributed Papers

Author: I.J. Scott, J. M. Izen, E.T. Simopoulos, H. Nicholson, Roger Barlow, Martino Margoni, Davide Piccolo, R.J. Plano, A. Santroni, S. Devmal, J. Stelzer, S. Ferrag, G. Della Ricca, P.F. Manfredi, Tim Adye, Valery I. Telnov, Daniele Del Re, David W.G.S. Leith, G. Dahlinger, D. A. Sanders, R. Bartoldus, Zongfu Yu, D.A. Bukin, C. Hast, D. J. Lange, G. Piredda, N. Copty, A. Dvoretskii, J. C. Chen, M. Morii, C. De La Vaissiere, M. Turcotte, Sh. Rahatlou, I. Kitayama, L. Del Buono, J. A. Nash, Joram Berger, Y. u. G. Kolomensky, J. M. Bauer, M. Iwasaki, L. Turnbull, C. H. Cheng, J.F. Kral, R. Muller Pfefferkorn, H. Zobernig, R. J. Wilson, C. Touramanis, L. M. Cremaldi, T.I. Meyer, M. Kalelkar, J. R. Fry, A. W. Borgland, D.E. Azzopardi, G. Grosdidier, U. Mallik, K. T. McDonald, Pierluigi Paolucci, D. G. Hitlin, P. Rankin, T. Dignan, Francesco Lanni, P. Strother, J.Y. Nief, R. Prepost, A. Romosan, P.F. Jacques, F. Galeazzi, E. Roussot, W. H. Toki, Bernard Denis, F. Forti, H. F.W. Sadrozinski, N. Neri, B. N. Ratcliff, Maddie Mc Kay, S. Playfer, C. P. O'Grady, M. Serra, A. V. Telnov, A. Kurup, C. C. Young, M. Bondioli, Simon George, T. Schalk, J. Fullwood, D. R. Muller, P. J. Clark, A. Hicheur, Sven Menke, M. A. Mazzoni, O. Hamon, G. Wormser, A.K. McKemey, A. Olivas, E. A. Kravchenko, M. Weaver, Hz Y. S., R. Schwierz, J. A. Kadyk, B. Di Girolamo, I. M. Peruzzi, A. M. Eisner, Randall P. Johnson, Willocq Stephane, C. Gatto, R. N. Cahn, P. Sanders, Owen Rosser Long, R. W. Kadel, V.V. Serbo, A. Seiden, D. Su, D. Kirkby, G. Vasseur, H. A. Neal, Mathieu Langer, J. Blouw, Maria Roberta Monge, Larry D. Gladney, R. S. Panvini, S. L. Levy, E. Paoloni, Klaus R. Schubert, D. Falciai, Roland Bernet, P. G. Bright Thomas, M.O. Dima, W. Dunwoodie, W. Bugg, S. Bettarini, J.D. McFall, F. Muheim, P.B. Vidal, M. V. Purohit, M. T. Ronan, A. J. S. Smith, W. Bhimji, William S. Lockman, A. Zallo, G.L. Godfrey, Paul Dauncey, F. Colecchia, G. P. Dubois Felsmann, J. Albert, R.J.L. Potter, M. Piccolo, H. O. Cohn, G. Batignani, N. A. Roe, S. Farinon, W. T. Meyer, M. Prest, D.L. Wagner, A. A. Grillo, D. R. Johnson, M. Benkebil, Ren-Yuan Zhu, K. Paick, J. J. Back, Torre Wenaus, J. Krug, S. Versille, C. Thiebaux, Michael S. Witherell, S. Petrak, S. M. Spanier, S. I. Serednyakov, F. Bianchi, David Wallom, T.L. Geld, M. Mandelkern, A. W. Weidemann, F. Bulos, K. Fratini, H. Marsiske, P. Fabbricatore, A. Woch, J. W. Lamsa, V. Zacek, R. Seitz, J. Chauveau, S. Jayatilleke, T. Schietinger, S. Otto, C. Campagnari, A. R. Buzykaev, C. Voci, Stephane T'Jampens, M. S. S. Gill, H. Staengle, Asoka S. De Silva, F. Le Diberder, Pu Wang, H.A. Tanaka, S. Emery, D. S. Best, C. Patrignani, J. P. Lees, R. de Sangro, V. Tisserand, T.M.B. Kordich, G. W. London, A. B. Breon, Maurizio Lo Vetere, M. Carpinelli, M.G. Pia, C. Dallapiccola, S. J. Yellin, W. Verkerke, J.R. Johnson, M. Rotondo, M. Dickopp, S. J. Gowdy, G. Triggiani, J. Lory, V. Lillard, Corrado Angelini, S. Passaggio, A. Smol, T. Deppermann, Mario Giorgi, Michael Steinke, B. Spaan, Giovanni Crosetti, Patrick Robbe, D. Thiessen, R. Aleksan, E.D. Frank, A. Frey, J. Schwiening, A. V. Gritsan, S. F. Ganzhur, H. R. Band, R. E. Schmitz, C. P. Jessop, A. N. Yushkov, H. Briand, A. D. Bukin, D. J. Knowles, Morganti Silvio, F. X. Yumiceva, J. Cochran, N. Cavallo, J. J. Walsh, Qi N. D., M. Folegani, William J. Wisniewski, A. J.R. Weinstein, G. Michelon, Gabriella Sciolla, A. Tumanov, A. Palano, Y. B. Pan, G. Blaylock, C. Bozzi, G. Cowan, Stéphane Plaszczynski, C. Lu, D. Judd, M. K. Sullivan, E. Treadwell, Ch. Bula, S. Christ, G. S. Abrams, B. A. Schumm, Jochen Schieck, D. Zanin, R. Faccini, G. Simi, F. Ferrarotto, A. J. Lankford, M.G. Wison, R. Kowalewski, J. Oyang, M.L. Aspinwall, R. C. Field, F. Salvatore, K.C. Moffeit, C. A. Heusch, M. R. Convery, G. Finocchiaro, B. T. Meadows, A. Buzzo, Frank Jackson, S. M. Xella, G. Cavoto, H. B. Crawley, G. Vuagnin, G. De Nardo, J. D. Richman, Jan Stark, Sercan Sen, Stephen J. McMahon, T. S. Mattison, Helen R. Quinn, V. Luth, Teresa Barillari, Bryan Dahmes, R. M. Bionta, V. B. Golubev, G. D. Lafferty, N. Chevalier, M. Posocco, H. Schmuecker, P. Patteri, L. Piemontese, D. J. B. Smith, L. Behr, G. Raven, M. D. Sokoloff, C. M. Brown, N. Dyce, Aron Soha, A. Snyder, L. Lanceri, R. C. W. Henderson, E. Gabathuler, F. C. Porter, Jayashree Roy, J.P. Martin, P. J. Oddone, D. Lavin, D.A. Roberts, E. Lamanna, Crisostomo Sciacca, D. Aston, J. H. Von Wimmersperg Toeller, M. M. Macri, D.P. Coupal, J. O. Nielsen, G. Rizzo, T. A. Gabriel, A. Valassi, A. Jawahery, Sandrine Laplace, V.G. Shelkov, Stefan Kluth, Vuko Brigljevic, J. Va’vra, P. Poropat, T. Handler, A. Gaidot, E. Maly, Michael Doser, Aubert Bernard, R. J. Sloane, P. R. Burchat, H. W. Shorthouse, S. Trincaz Duvoid, F. F. Wilson, A. R. Clark, G. P. Gopal, N. Kuznetsova, T. Himel, Peter Elmer, M. Rama, A. P. Onuchin, P. N. Y. David, H. Park, G.P. Chen, Allison John, R. Cowan, E. I. Rosenberg, J. A. McKenna, Paola Grosso, A. A. Salnikov, P. Dixon, R. Liu, F. Anulli, I. Adam, F. Dal Corso, T. B. Moore, E. Chen, Q. H. Guo, B. Stugu, A. M. Eichenbaum, Bona Marcella, G. R. Bonneaud, P.L. Anthony, R. Parodi, Alexis Pompili, Tetiana Hryn'ova, S. Dittongo, D. J. Payne, U. Nauenberg, Enrico Robutti, S. Ricciardi, Russell S. Hamilton, J. Dorfan, Amir Ahsan, S. H. Robertson, B. Serfass, N. Savvas, A. M. Boyarski, A. Samuel, Benayoun Maurice, Sridhara Dasu, A.C. Forti, C. Cartaro, W. Kozanecki, B. Franek, Herbert Koch, Tiehui Liu, C. Voena, A. Hauke, M. Booke, K. T. Flood, R. Frey, M. H. Kelsey, C. C. Buchanan, Brad Abbott, David Nathan Brown, M. Verderi, Ph Leruste, M. Turri, P. F. Giraud, M. Momayezi, C. LeClerc, B. Mayer, Y. I. Skovpen, Monika Grothe, R. Messner, L. T. Kerth, Marcel Kunze, D.E. Dorfan, G. Rong, Stanley S. Hertzbach, G. Vasileiadis, S. Luitz, D.H. Coward, V. Eschenburg, A. Lu, H. Hu, D. C. Williams, P. Taras, Elliott D. Bloom, Scott D. Metzler, L.S. Rochester, J. M. Roney, Luca Lista, R. Musenich, V. E. Blinov, W.A. Wenzel, L. Bosisio, T.R. McMahon, R. C. Penny, David Norvil Brown, P. C. Bloom, M. Falbo, K. Goetzen, Yuehong Xie, P.L. Reinertsen, V. Miftakov, W. N. Cottingham, M. Morandin, C. Yeche, G. Calderini, M. H. Schune, C. E. Marker, E. Charles, F. Sandrelli, R. Contri, R. Stroili, C. Borean, F.C. Pastore, Anders Ryd, Hocker Andreas, F. E. Taylor, M. Pripstein, M.E. Huffer, A. M. Lutz, K. van Bibber, S. W. O'Neale, V. Lepeltier, J.H. Weatherall, N. R. Barlow, B. Foster, F. Palombo, Vivek Sharma, J. Olsen, S.F. Schaffner, Marco Pallavicini, M.E. Levi, Peter S. Kim, P. McGrath, Michael C. Carroll, William T. Ford, D. Boutigny, D. H. Wright, S. Fahey, T. Glanzman, E. Vallazza, F. Brochard, S. B. Chun, S. Yang, Francesco Fabozzi, J. Trischuk, Y. Groysman, N. I. Geddes, L. Wilden, C.S. Sutton, G. Lynch, James G. Smith, S. Prell, G. Eigen, M. L. Kocian, F. Safai Tehrani, Jie Zhang, B. Lewandowski, A. Anjomshoaa, D. B. MacFarlane, E. W. Varnes, Craig R. Wuest, A. Soffer, J. Brose, Kazuo Abe, A. Lusiani, A. Calcaterra, J.R.G. Alsmiller, J. G. Branson, W. Kroeger, R. R. Kofler, M. Krishnamurthy, K.G. Baird, N. De Groot, N.J.W. Gunawardane, S. Bagnasco, C. Roat, D. E. Wagoner, D. Gamba, D. P. Stoker, Benjamin Brau, C. L. Davis, Ivo M. Gough Eschrich, R. Gamet, W. C. van Hoek, P.A. Hart, Douglas Wright, M. Haire, Langenegger Urs, Leonardi Emanuele, G. Vaitsas, C. Priano, Wu S. L., M. Mugge, J. E. Brau, J.M. Gaillard, M.I. Williams, Y. Karyotakis, F. Di Lodovico, V. N. Ivanchenko, V. Speziali, C. M. Hawkes, P. F. Harrison, X. Shi, Amir Farbin, A. Khan, V. Re, K. Arisaka, T. J. Harrison, Richard Mount, J.J. Reidy, R. Waldi, R. S. Dubitzky, J. M. LoSecco, J.E. Swain, N. B. Sinev, Simon Jolly, H. M. Lacker, Wolfgang Walkowiak, H. L. Lynch, R. G. Jacobsen, P.A. Fischer, D. M. Strom, A. Dorigo, C. Hearty, D. J. Summers, T. J. Brandt, Janice Button Shafer, A. Perazzo, M. Milek, Ingrid U. Scott, F. Simonetto, R. H. Schindler, R. Baldini Ferroli, Krisztian Peters, R. Kroeger, Richard O. Claus, A. T. Watson, A. B. Meyer, X. C. Lou, A. Roodman, T. Pulliam, F. Ferroni, J. Beringer, D. A. Bowerman, P. M. Patel, Stephen Robert Wagner, J.H. Panetta, M. George, N. K. Watson, T. Colberg, U. Egede, J. Cohen Tanugi, Jane S. Tinslay, M. L. Perl, G. De Domenico, J. T. Boyd, Walter R. Innes, Lydia Roos, F. Martinez Vidal, M. Morganti, J.C. Andress, John L. Harton, M. Zito, A. A. Korol, R. K. Yamamoto, M. G. Green, H. Singh, E. Torassa, and G. Mancinelli
Subjects: Branching (linguistics), Physics, Nuclear and High Energy Physics, Particle physics, Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics
Published: 2002

19. Search for leptoquarks in electron–photon scattering at up to 209 GeV at LEP

Author: G. Abbiendi, C. Ainsley, P.F. Åkesson, G. Alexander, J. Allison, G. Anagnostou, K.J. Anderson, S. Arcelli, S. Asai, D. Axen, G. Azuelos, I. Bailey, E. Barberio, R.J. Barlow, R.J. Batley, P. Bechtle, T. Behnke, K.W. Bell, P.J. Bell, G. Bella, A. Bellerive, G. Benelli, S. Bethke, O. Biebel, I.J. Bloodworth, O. Boeriu, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, L. Brigliadori, R.M. Brown, H.J. Burckhart, J. Cammin, S. Campana, R.K. Carnegie, B. Caron, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, P.E.L. Clarke, E. Clay, I. Cohen, J. Couchman, A. Csilling, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, A. De Roeck, E.A. De Wolf, P. Dervan, K. Desch, B. Dienes, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, E. Etzion, F. Fabbri, L. Feld, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, M. Giunta, J. Goldberg, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, A. Gupta, C. Hajdu, M. Hamann, G.G. Hanson, K. Harder, A. Harel, M. Harin-Dirac, M. Hauschild, J. Hauschildt, C.M. Hawkes, R. Hawkings, R.J. Hemingway, C. Hensel, G. Herten, R.D. Heuer, J.C. Hill, K. Hoffman, R.J. Homer, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, K. Ishii, A. Jawahery, H. Jeremie, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, T.P. Kokott, S. Komamiya, L. Kormos, R.V. Kowalewski, T. Krämer, T. Kress, P. Krieger, J. von Krogh, D. Krop, T. Kuhl, M. Kupper, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, I. Lawson, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, J. Lillich, C. Littlewood, S.L. Lloyd, F.K. Loebinger, J. Lu, J. Ludwig, A. Macchiolo, A. Macpherson, W. Mader, S. Marcellini, T.E. Marchant, A.J. Martin, J.P. Martin, G. Martinez, G. Masetti, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, T.J. McMahon, R.A. McPherson, F. Meijers, P. Mendez-Lorenzo, W. Menges, F.S. Merritt, H. Mes, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, S. Moed, W. Mohr, T. Mori, A. Mutter, K. Nagai, I. Nakamura, H.A. Neal, R. Nisius, S.W. O'Neale, A. Oh, A. Okpara, M.J. Oreglia, S. Orito, C. Pahl, G. Pásztor, J.R. Pater, G.N. Patrick, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, O. Pooth, A. Quadt, K. Rabbertz, C. Rembser, P. Renkel, H. Rick, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, Y. Rozen, K. Runge, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, E.K.G. Sarkisyan, A.D. Schaile, O. Schaile, P. Scharff-Hansen, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, F. Spano, M. Sproston, A. Stahl, K. Stephens, D. Strom, R. Ströhmer, B. Surrow, S. Tarem, M. Tasevsky, R.J. Taylor, R. Teuscher, J. Thomas, M.A. Thomson, E. Torrence, D. Toya, T. Trefzger, A. Tricoli, I. Trigger, Z. Trócsányi, E. Tsur, M.F. Turner-Watson, I. Ueda, B. Ujvári, B. Vachon, C.F. Vollmer, P. Vannerem, M. Verzocchi, H. Voss, J. Vossebeld, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Branching fraction, High Energy Physics::Phenomenology, Scalar (mathematics), Supersymmetry, Electron, 01 natural sciences, First generation, Standard Model, 0103 physical sciences, High Energy Physics::Experiment, Leptoquark, 010306 general physics, Photon scattering
Abstract: Searches for first generation scalar and vector leptoquarks, and for squarks in R-parity violating SUSY models with the direct decay of the squark into Standard Model particles, have been performed using e+e- collisions collected with the OPAL detector at LEP at e+e- centre-of-mass energies between 189 and 209 GeV. No excess of events is found over the expectation from Standard Model background processes. Limits are computed on the leptoquark couplings for different values of the branching ratio to electron-quark final states.
Published: 2002

20. Measurement of the branching ratio for →τ decays

Author: J. Letts, A. Leins, Shlomo Dado, K. Graham, Tara Shears, P. Gagnon, D. Toya, A. W. Lloyd, C. Pahl, Paolo Giacomelli, M. Hauschild, Giora Mikenberg, G. D. Lafferty, J. Allison, Zoltan Laszlo Trocsanyi, M. Harin-Dirac, C. H. Shepherd-Themistocleous, Kiyotomo Kawagoe, Dong Hee Kim, R. J. Homer, I. J. Bloodworth, A. K. Honma, O. Runolfsson, Gideon Bella, Claudio Grandi, J. S. White, Claudia Schmitt, W. J. McDonald, B. C. Shen, David Futyan, Yoram Rozen, H. J. Burckhart, D. J. Miller, M. Donkers, Naoko Kanaya, Siegfried Bethke, Alexander Oh, S. Yamashita, P. Igo-Kemenes, M. A. Thomson, P. F. Åkesson, D. Lanske, G. W. Wilson, Junichi Kanzaki, P. G. Estabrooks, R. K. Keeler, G. Gaycken, Gregor Herten, W. G. Scott, J. Polok, D. Karlen, T. Trefzger, S. Spagnolo, K. Ishii, H. Jeremie, S. D. Talbot, C. Hensel, Daniel Lellouch, I. Nakamura, Richard J. K. Taylor, T. Behnke, Takehiko Mori, C. R. Jones, A. Okpara, J. W. Gary, Arnulf Quadt, P. M. Watkins, C. F. Vollmer, T. R. Wyatt, R. J. Barlow, H. Landsman, J. E. Pilcher, Erez Etzion, K. R. Hossain, P. Mättig, D. Zer-Zion, O. Schaile, M. Verzocchi, A. J. Martin, Christoph Geich-Gimbel, P. Mendez-Lorenzo, Thorsten Wengler, Stefan Kluth, Shlomit Tarem, B. Caron, D. Axen, P. Renkel, A. Jawahery, Oana Elena Vickey Boeriu, D. Glenzinski, Marek Tasevsky, F. G. Oakham, A. D. Schaile, Gabriella Pasztor, Dezso Horvath, M. J. Losty, E. L. Barberio, F. Spano, Peter Sherwood, A. Macchiolo, J. Couchman, W. Mader, F. Odorici, T. Kress, B. Surrow, A. A. Carter, P. Vannerem, G. A. Snow, C. P. Ward, J. Ludwig, K. Runge, P. Bock, G. Benelli, L. Brigliadori, Shoji Asai, E. A. De Wolf, S. Rosati, Sachio Komamiya, Giovanni Abbiendi, M. J. Oreglia, A. Csilling, S. Söldner-Rembold, Dave Charlton, J. G. Layter, S. W. O'Neale, K. Hoffman, A. Harel, S.J. Dallison, T. P. Kokott, D. Waller, P. O. Günther, T. Saeki, Rolf Seuster, M. Gruwé, G. N. Patrick, P. E.L. Clarke, Ikuo Ueda, D. M. Strom, K. J. Anderson, V. Kartvelishvili, J. P. Martin, T. Kuhl, R. D. Heuer, Richard Nisius, W. Menges, Achim Stahl, J. Lu, Satoshi Mihara, Guenter Duckeck, H. Rick, C. Y. Chang, Marco Cuffiani, M. Ford, G. Anagnostou, Katja Klein, L. Stumpf, H. Voss, H. Mes, I. P. Duerdoth, S. Braibant, K. Sachs, J. R. Carter, Norbert Wermes, Sherry Towers, T. Kawamoto, G. G. Hanson, N. K. Watson, G. Giacomelli, J. Grunhaus, S. Orito, G. P. Siroli, I. Lawson, Frank Fiedler, A. De Roeck, M. Kobel, Christoph Schwick, J. Böhme, M. S. Dixit, T. R. Junk, Raimund Ströhmer, Richard Teuscher, Frans Meijers, Juergen Thomas, Matthias Schröder, P. S. Wells, T. Kämer, C. Ainsley, P. Hüntemeyer, A. T. Watson, Andris Skuja, A. M. Rossi, Georges Azuelos, B. Vachon, O. Sahr, E. Tsur, C. M. Hawkes, R. Liebisch, Isabel Marian Trigger, K. W. Bell, A. Macpherson, R. J. Hemingway, Tetsuro Mashimo, R. Kowalewski, J. C. Hill, J. Lillich, M. F. Turner-Watson, Beatrix Dienes, Paul Kyberd, F. K. Loebinger, B. W. Kennedy, R. J. Sobie, Joost Vossebeld, P. Jovanovic, E. Torrence, Austin Ball, S. Arcelli, Klaus Desch, R. Howard, Peter Krieger, Alessandro Montanari, M. Kupper, K. Stephens, Ivor Fleck, Joleen Pater, Edward K. G. Sarkisyan, A. Klier, H. A. Neal, Alain Bellerive, N. L. Rodning, Thomas E Marchant, C. Littlewood, P. Dervan, B. Poli, P. Scharff-Hansen, A. M. Smith, Daniele Bonacorsi, D. Krop, J. von Krogh, Gideon Alexander, James Pinfold, R. J. Hawkings, Oliver Pooth, D. Wetterling, Paolo Capiluppi, T. J. McMahon, J. Dubbert, R. K. Carnegie, M. Schumacher, Richard Batley, V. Zacek, J. A. Wilson, D. R. Ward, G. Karapetian, R. G. Kellogg, C. Sbarra, Csaba Hajdu, Stefano Marcellini, J. Goldberg, I. Cohen, Christoph Rembser, A. Fürtjes, Lutz Feld, M. Fanti, Ehud Duchovni, M. Boutemeur, F. S. Merritt, J. A. McKenna, A. Michelini, Robert McPherson, T. Kobayashi, Fabrizio Fabbri, A. Frey, J. Cammin, K. Harder, R. M. Brown, Lorne Levinson, G. D. Long, I. R. Bailey, Klaus Rabbertz, Stephen Lloyd, O. Biebel, D. R. Rust, D. E. Plane, G. M. Dallavalle, K. Roscoe, A. Gupta, E. Clay, J. M. Roney, Koichi Nagai, W. Mohr, P. Ferrari, German Martinez, E. K. U. Gross, and M. Sproston
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Branching fraction, Electron–positron annihilation, Hadron, 01 natural sciences, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Exponential decay, Nuclear Experiment, 010306 general physics
Abstract: Using about 3.9 million hadronic Z decays from e + e − collisions recorded by the OPAL detector at LEP at centre-of-mass energies s ≈M Z , the branching ratio for the decay D − s →τ − ν τ has been measured to be BR ( D − s →τ − ν τ )=(7.0±2.1( stat )±2.0( syst ))%. This result can be used to derive the decay constant of the D − s meson: f D s =(286±44( stat )±41( syst )) MeV .
Published: 2001

21. Measurement ofCP-Violating Asymmetries inB0Decays toCPEigenstates

Author: J. Chauveau, J. E. Rasson, J. Nielsen, R. R. Kofler, D. E. Wagoner, A. Kurup, D. McShurley, B. Claxton, Gabriele Simi, R. Contri, P. L. Reinertsen, C. L. Davis, J. D. McFall, T. J. Harrison, R. Prepost, M. Haire, J. Va'vra, Richard Mount, J.L. Hewett, J.J. Reidy, P.F. Jacques, J. Oyang, I. Kitayama, Matteo Rama, P. F. Kunz, J. Lidbury, C. D. Buchanan, M. S. Dubrovin, Helen R. Quinn, J. Hanson, A. Hasan, A. Soha, P. G. Bright-Thomas, V. B. Golubev, R. Reif, R. Aleksan, J.F. Kral, S. Petrak, M. Krishnamurthy, J. M. LoSecco, J.E. Swain, L. Sapozhnikov, A. Olivas, Bernard Aubert, A. Gaidot, D. J. Payne, E. A. Kravchenko, U. Nauenberg, G. P. Gopal, A. Samuel, M. Doser, H. Lebbolo, Tiehui Liu, G. Vaitsas, B. Dahmes, G. Manzin, R. J. Sloane, D. Breton, James H Cochran, Marcel Kunze, S. F. Dow, M. Benayoun, A. Anjomshoaa, S. Dardin, S. Patton, N. B. Sinev, G. De Nardo, S. Luitz, A. R. Clark, G. Mancinelli, G. Calderini, C. Hast, R. Baldini-Ferroli, K. T. McDonald, Pierluigi Paolucci, D. Kirkby, G. Vasseur, F. Galeazzi, Roland Martin, K. Marks, Y. S. Zhu, T.M.B. Kordich, S. Devmal, D. Judd, J. M. Bauer, S. McMahon, Zongfu Yu, D. Bernard, Y. Karyotakis, F. Di Lodovico, M. Turri, C. De La Vaissiere, C. Dallapiccola, O. H. Saxton, E. Maly, Roland Bernet, C. T. Boeheim, G. Haller, L.S. Rochester, J. L. Harton, S. W. K. Emery, W. Orejudos, G. Lynch, P. David, J. M. Roney, Mossadek Talby, Wolfgang Walkowiak, H. L. Lynch, M. Turcotte, A. W. Weidemann, R. G. Jacobsen, Douglas Wright, S. F. Ganzhur, H. R. Band, R. E. Schmitz, P. Bailly, A. Höcker, E.N. Spencer, Luca Lista, J. R. Fry, G. W. London, N. R. Barlow, R. Coombes, P. McGrath, C. Renard, S. Fahey, F. Gaede, J. G. Smith, C. P. Jessop, S. Dû, J. Zhang, K. T. Flood, G. Rizzo, A. Zallo, G.L. Godfrey, O. Hamon, V. Eschenberg, D. Nelson, D. R. Quarrie, S. Prell, F. Colecchia, Sven Menke, S. D. Ecklund, F. Bulos, V. Speziali, A. K. McKemey, V. G. Shelkov, W. Burgess, W. S. Lockman, A. A. Salnikov, M. Dickopp, J. A. Nash, M. Lo Vetere, L. A. Klaisner, C. M. Hawkes, X. Shi, C. le Clerc, S. A. Lewis, A. Valassi, Yuehong Xie, V. Miftakov, P.A. Fischer, D. M. Strom, G. Michelon, H. W. Shorthouse, J. Ohnemus, S.M. Jayatilleke, V. Zacek, T. Schietinger, T. Weber, R.J. Plano, A. Mokhtarani, A. Santroni, P. Poropat, J. Pavlovich, Amir Farbin, Justin Albert, Y. I. Skovpen, R. Messner, C. H. Cheng, A. Kirk, J. Schwiening, S. S. Hertzbach, Y. Groysman, A. Hanushevsky, D.H. Coward, B. Byers, D. Su, Mathieu Langer, A. J.S. Smith, G. Rong, C.S. Lin, S. Jayatilleke, H. A. Tanaka, M. R. Convery, D. Warner, H. von der Lippe, A. N. Yushkov, M. Kalelkar, R. Krause, G. S. Abrams, M. Folegani, S. Sen, Philip James Clark, M. Iwasaki, L. Turnbull, Marcello Rotondo, R. J. Wilson, Owen Rosser Long, F. Bronzini, A. Seiden, X. C. Lou, J. J. Walsh, A. Tumanov, M. L. Kocian, L. Cottrell, C. Lionberger, S. Galagedera, Ralph Müller-Pfefferkorn, J. MacDonald, I.J. Scott, P. Besson, D. Newman-Coburn, M. Nyman, J. Lamsa, D. A. Roberts, F.C. Pastore, F. E. Taylor, P. Taras, P. Dixon, D. Gamba, S. Trincaz-Duvoid, Michael Sokoloff, T. Handler, N. K. Watson, Alexander Grillo, P. Eckstein, T. Colberg, John Back, D. R. Freytag, R. Seitz, Stephane T'Jampens, V. le Peltier, J. H. von Wimmersperg-Toeller, Jamie Boyd, B. Camanzi, V. E. Blinov, A. Frey, A. W. Borgland, G. Batignani, G. Grosdidier, James S. Harris, G. Finocchiaro, G. R. Bonneaud, J. Dorfan, Amir Ahsan, D. N. Brown, A.K. Michael, L. M. Cremaldi, J. Roy, R. de Sangro, S. L. Wu, T. R. McMahon, C. Angelini, S. Kyre, R. S. Dubitzky, A. Pompili, A. M. Boyarski, J. P. Lees, Vladimir Ivanchenko, U. Egede, Paola Grosso, Wouter Verkerke, F. Simonetto, G. Sciolla, M. George, R. H. Schindler, F. R. Goozen, D. S. Brown, U. Langenegger, J. Lory, M. Mandelkern, K. Ford, Craig R. Wuest, T. Fieguth, P. Bourgeois, M. Grothe, R. N. Cahn, S. Kluth, P. J. Oddone, Maria Roberta Monge, T. Dignan, John E. Bartelt, E.T. Simopoulos, H. Nicholson, B. Abbott, M. Beaulieu, W. H. Toki, A. Brooks, A. Jeremie, Mario Giorgi, I. De Bonis, Jane S. Tinslay, L. Del Buono, Claudio Campagnari, B. Lewandowski, J. E. Brau, Martino Margoni, H. Zobernig, K. Skarpass, J.L. Heck, E. Borsato, M. Piccolo, E. L. Hart, E. Chen, Q. H. Guo, B. Stugu, G. De Domenico, S. Versille, H. Staengle, W. W. Craddock, N. De Groot, D. B. MacFarlane, F. Brochard, Ph Leruste, S. Morganti, Sridhara Dasu, Bruce Schumm, J. A. McKenna, M. Serra, H. Kawahara, S. Jolly, D. G. Hitlin, Robert Henderson, P. Rankin, J.T. Seeman, J. N. Albert, D. E. Dorfan, S. Chun, W. Pope, Joseph Izen, S. W. O'Neale, M. Momayezi, N. A. Roe, D. Zanin, Mauro Morandin, M. Carpinelli, Lydia Roos, B. Mayer, A. de Silva, A. J.R. Weinstein, L. Keller, R. Kroeger, C. Gatto, Krisztian Peters, A. Mass, E. Paoloni, F. Forti, P.B. Vidal, J. Stelzer, A. Lu, Elliott D. Bloom, Scott D. Metzler, Marco Pallavicini, U. Wienands, P.L. Anthony, L. Behr, T.J. Pavel, Francesco Lanni, J. Button-Shafer, W. Kroeger, P. Strother, J.M. Gaillard, D. Boutigny, M. Morganti, C. Bula, Johann Cohen-Tanugi, F. Muheim, J.C. Andress, P.F. Manfredi, A. T. Watson, R. C. Jared, S. Yang, W. A. Wenzel, D. W. G. S. Leith, Francesco Fabozzi, S. Bettarini, W. N. Cottingham, S. Metcalfe, Dc Williams, T. Benninger, W. T. Ford, R. J. Thompson, D.L. Wagner, Tim Adye, K. Fratini, Valerio Re, M. M. Macri, Rana R. McKay, Andrei Gritsan, R. Frey, B. T. Meadows, M. H. Kelsey, A. B. Breon, W. M. Bugg, Alberto Lusiani, E. Roussot, H. F.W. Sadrozinski, Nicola Neri, J. Trischuk, T. Schalk, George Lafferty, C. Hearty, F. Ferrarotto, A. A. Korol, G. Vasileiadis, G. Triggiani, G. Raven, E. Charles, P. Kim, S. L. Levy, N. Kuznetsova, A. M. Eisner, Tom Elioff, C. M. Brown, D. J. Summers, P. F. Harrison, M. Bondioli, P. R. Burchat, N. Savvas, A. Buccheri, J. Brose, M. A. Mazzoni, G. Wormser, A. Calcaterra, R. K. Yamamoto, Wahid Bhimji, K. Baird, G. Zioulas, J. R. Johnson, Emilio Leonardi, A. V. Telnov, C. Bozzi, Fergus Wilson, I. Kipnis, J. F. Genat, R. Stone, B. Pedrotti, J.R.G. Alsmiller, J. Y. Nief, G. Putallaz, K. Truong, C. E. Marker, Jacek Becla, C. Roat, H. Singh, J. Stark, D. Oshatz, F. Anulli, A. Perazzo, M. Milek, C. Voena, A. Roodman, F. Martinez-Vidal, S. Willocq, D. P. Stoker, Dominik Müller, Willem G. J. Langeveld, B. Serfass, S. Dittongo, Filippo Bosi, T. I. Meyer, T. Pulliam, S. H. Robertson, I. M. Peruzzi, Roland Waldi, F. G. O'Neill, G. Della Ricca, Patrick Robbe, D. Thiessen, L. Wilden, F. Ferroni, G. Hamel de Monchenault, V.V. Serbo, R. S. Panvini, D. Falciai, P.A. Hart, J. J. Russell, E.D. Frank, W. Dunwoodie, A. Jawahery, R. Bard, Y. B. Pan, R. Kowalewski, Q. Fan, Ingrid U. Scott, M. Booke, S. I. Serednyakov, F. Bianchi, David Wallom, R. Fernholz, Bruce E. Sands, M. Verderi, Darren Price, D. A. Bowerman, R. Bartoldus, M.L. Aspinwall, A. Buzzo, R. J. Barlow, I. Gaponenko, P. Sanders, M. Pripstein, P. M. Patel, M. V. Purohit, A. B. Meyer, Stefan M Spanier, V. I. Telnov, F. X. Yumiceva, G. Crosetti, Stephen Robert Wagner, J.H. Panetta, Pu Wang, James L. White, Yg Kolomensky, C. Beigbeder, K. R. Schubert, F. Gastaldi, L. Gladney, R.J.L. Potter, R. Faccini, K. van Bibber, Lodovico Ratti, V. Brigljević, J. A. Kadyk, A. J. Lankford, Enrico Robutti, M. Marino, K. Paick, U. Mallik, M. Reep, F. Le Diberder, S. M. Xella, C. Cartaro, Marcella Bona, J. D. Richman, B. Franek, N. Chevalier, M. Posocco, C. Peters, M. Benkebil, L. T. Kerth, J.H. Weatherall, D.P. Coupal, B. Foster, G. A. Cowan, C. Thiebaux, F. Palombo, Vivek Sharma, J. Fullwood, G. M. Kolachev, G. Blaylock, Michael C. Carroll, G. Vuagnin, M. Nordby, M. Marzolla, A. Smol, Michael S. Witherell, P. E. Raines, W. Kozanecki, T.L. Geld, M. T. Ronan, R. Lafever, A. Romosan, L. Gosset, A. P. Onuchin, G. P. Dubois-Felsmann, G.P. Chen, S. K. Louie, P. D. Dauncey, Peter Elmer, C. Patrignani, A. R. Buzykaev, I. Eschrich, V. Tisserand, M. Long, N. Copty, H. Schmuecker, M. S. Gill, J. L. Wittlin, B. Yamamoto, Luciano Bosisio, J. P. Martin, D. J. Knowles, T. G. O'Connor, R. W. Kadel, L. Piemontese, R. Claus, A. Palano, T. B. Moore, E. Gabathuler, W. R. Innes, A. Soffer, F. C. Porter, J. Krug, I. Adam, H.J. Krebs, R. Cizeron, R. Cowan, M. Weaver, G. Cavoto, R. P. Johnson, J. R. Schieck, V. Lillard, T. Deppermann, Stephen Gowdy, Ren-Yuan Zhu, H. B. Crawley, David J. Smith, C. A. Heusch, J. Perl, H. Marsiske, S. Bagnasco, Yang Li, Ezio Torassa, A. M. Lutz, W. J. Wisniewski, D. Del Re, S. J. Yellin, M. I. Williams, S. Passaggio, C. Voci, E. Lamanna, Crisostomo Sciacca, D. Aston, F. Jackson, Michael Levi, B. Brau, C. Touramanis, H. O. Cohn, D.E. Azzopardi, F. Dal Corso, G. Dahlinger, T. S. Mattison, D. A. Sanders, D.A. Bukin, D. J. Lange, G. Piredda, A. Dvoretskii, J. C. Chen, M. E. Huffer, L. Martin, M. Morii, Sh. Rahatlou, Maria Grazia Pia, S. Playfer, C. P. O'Grady, Akram Khan, R. Gamet, B. Di Girolamo, N. Dyce, T. J. Wenaus, E. I. Rosenberg, C. T. Day, T. Glanzman, Mg Green, Daniel Johnson, J. Olsen, M. Zisman, P. Patteri, O. Fackler, M. McCulloch, R. Bell, G. Oxoby, M. K. Sullivan, E. Treadwell, B. Zhang, Simon George, N. J.W. Gunawardane, Herbert Koch, R. C. Field, F. Salvatore, K.C. Moffeit, P. Matricon, V. Luth, S.C. Berridge, F. Sandrelli, R. M. Bionta, H. de Staebler, A. Snyder, C. Lu, T. A. Gabriel, H. Futterschneider, G. Fouque, T. Himel, R. Boyce, S. Otto, E. W. Varnes, Achim Stahl, John Allison, S. Ferrag, S. Burke, B. Spaan, H. Briand, A. D. Bukin, N. Cavallo, L. Lanceri, Stéphane Plaszczynski, J. Beringer, C. Bulfon, S. F. Schaffner, B. N. Ratcliff, N. D. Qi, R. Schwierz, M. Mugge, M. Zito, D. Fujino, Dave Britton, C. C. Young, W. T. Meyer, J. Blouw, Davide Piccolo, H. Hu, A. Karcher, M. Kay, P. C. Bloom, R. Hamilton, M. Falbo, Harold S. Park, P. Mora de Freitas, C. Yeche, M. H. Schune, T. Brandt, R. Stroili, H. A. Neal, A. Ryd, W. C. van Hoek, M. Steinke, N. I. Geddes, C.S. Sutton, G. Eigen, F. Safai Tehrani, Daniel E. Hale, and Kazuo Abe
Subjects: Physics, Particle physics, 010308 nuclear & particles physics, Electron–positron annihilation, media_common.quotation_subject, General Physics and Astronomy, 01 natural sciences, Asymmetry, Standard Model, B-factory, Nuclear physics, Particle decay, Amplitude, 0103 physical sciences, CP violation, High Energy Physics::Experiment, B meson, 010306 general physics, media_common
Abstract: We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta = 0.34+/-0.20 (stat)+/-0.05 (syst).
Published: 2001

22. Future direct dark matter search experiments

Author: V. Zacek
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Cold dark matter, Weakly interacting massive particles, Hot dark matter, Dark matter, Cosmic microwave background, Dark energy, Scalar field dark matter, Astrophysics::Cosmology and Extragalactic Astrophysics, Light dark matter, Atomic and Molecular Physics, and Optics
Abstract: Recent results of precise measurements of the cosmic microwave background anisotropy appear to strengthen the non-baryonic cold dark matter scenario. However the outcome of the present round of direct dark matter experiments is not conclusive and latest theoretical predictions of supersymmetric cross sections which take into account current accelerator limits and cosmological constraints tend to predict rather small interaction rates beyond the detection capabilities of present experiments. A new generation of detectors employing larger mass and sophisticated background suppression techniques promises a gain in sensitivity of two to three orders of magnitude.
Published: 2001

23. Measurement of the B0 lifetime and oscillation frequency using →ℓ decays

Author: G. Abbiendi, K. Ackerstaff, C. Ainsley, P.F. Åkesson, G. Alexander, J. Allison, K.J. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, I. Bailey, A.H. Ball, E. Barberio, R.J. Barlow, S. Baumann, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, G. Benelli, S. Bentvelsen, S. Bethke, O. Biebel, I.J. Bloodworth, O. Boeriu, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, J. Cammin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, P.E.L. Clarke, E. Clay, I. Cohen, O.C. Cooke, J. Couchman, C. Couyoumtzelis, R.L. Coxe, A. Csilling, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, A. de Roeck, E. de Wolf, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, P.G. Estabrooks, E. Etzion, F. Fabbri, M. Fanti, L. Feld, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, D. Glenzinski, J. Goldberg, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, M. Harin-Dirac, A. Hauke, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, C. Hensel, G. Herten, R.D. Heuer, J.C. Hill, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, T.P. Kokott, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, M. Kupper, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, I. Lawson, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, J. Lillich, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Lu, J. Ludwig, A. Macchiolo, A. Macpherson, W. Mader, S. Marcellini, T.E. Marchant, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, T.J. McMahon, R.A. McPherson, F. Meijers, P. Mendez-Lorenzo, W. Menges, F.S. Merritt, H. Mes, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Oh, A. Okpara, M.J. Oreglia, S. Orito, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, O. Pooth, M. Przybycień, A. Quadt, C. Rembser, P. Renkel, H. Rick, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, K. Stoll, D. Strom, R. Ströhmer, L. Stumpf, B. Surrow, S.D. Talbot, S. Tarem, R.J. Taylor, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. Torrence, S. Towers, D. Toya, T. Trefzger, I. Trigger, Z. Trócsányi, E. Tsur, M.F. Turner-Watson, I. Ueda, B. Vachon, P. Vannerem, M. Verzocchi, H. Voss, J. Vossebeld, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Oscillation, 0103 physical sciences, Detector, 010306 general physics, 01 natural sciences
Abstract: The lifetime and oscillation frequency of the B0 meson has been measured using B0->D*+l-v decays recorded on the Z0 peak with the OPAL detector at LEP. The D*+ -> D0pi+ decays were reconstructed using an inclusive technique and the production flavour of the B0 mesons was determined using a combination of tags from the rest of the event. The results t_B0 = 1.541 +- 0.028 +- 0.023 ps, Dm_d = 0.497 +- 0.024 +- 0.025 ps-1 were obtained, where in each case the first error is statistical and the second systematic.
Published: 2000

24. Suitability of superheated droplet detectors for dark matter search

Author: R. Gornea, M. Di Marco, J. Vinet, I. Boussaroque, V. Pagé, V. Zacek, L. Lessard, and N. Boukhira
Subjects: Nuclear physics, Physics, Cold dark matter, WIMP, Physics::Instrumentation and Detectors, Hot dark matter, Dark matter, Neutralino, Scalar field dark matter, Warm dark matter, High Energy Physics::Experiment, Astronomy and Astrophysics, Light dark matter
Abstract: We have measured the sensitivity of superheated droplet detectors in different radiation environments and we discuss the suitability of this detection technique for the search of weakly interacting cold dark matter particles. In particular, we show that our new proposed detector based on superheated carbo-fluorates can be operated at ambient pressure and room temperature in a mode where it is almost exclusively sensitive to the nuclear recoils following neutralino interaction, which allows a powerful background discrimination. The potential of the detection technique is shown by deriving a limit on the spin-dependent neutralino cross-section, making use of the very favourable neutralino– 19 F interaction and background suppression.
Published: 2000

25. First measurement of the inclusive branching ratio of b hadrons to φ mesons in Z decays

Author: G. Abbiendi, K. Ackerstaff, C. Ainsley, P.F. Akesson, G. Alexander, J. Allison, K.J. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, I. Bailey, A.H. Ball, E. Barberio, R.J. Barlow, S. Baumann, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, O. Biebel, I.J. Bloodworth, P. Bock, J. Böhme, O. Boeriu, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, J. Cammin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, O.C. Cooke, J. Couchman, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, A. de Roeck, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, P.G. Estabrooks, E. Etzion, F. Fabbri, M. Fanti, L. Feld, P. Ferrari, F. Fiedler, I. Fleck, M. Ford, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, D. Glenzinski, J. Goldberg, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, C.K. Hargrove, M. Harin-Dirac, A. Hauke, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, C. Hensel, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, T. Kobayashi, M. Kobel, T.P. Kokott, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, M. Kupper, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, I. Lawson, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, J. Lillich, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Lu, J. Ludwig, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, T.E. Marchant, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, T.J. McMahon, R.A. McPherson, F. Meijers, P. Mendez-Lorenzo, F.S. Merritt, H. Mes, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Oh, A. Okpara, M.J. Oreglia, S. Orito, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, O. Przybycień, A. Quadt, C. Rembser, H. Rick, S.A. Robins, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, S. Schmitt, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, S. Tarem, R.J. Taylor, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. Torrence, S. Towers, T. Trefzger, I. Trigger, Z. Trócsányi, E. Tsur, M.F. Turner-Watson, I. Ueda, P. Vannerem, M. Verzocchi, H. Voss, J. Vossebeld, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Meson, Branching fraction, High Energy Physics::Phenomenology, Hadron, Detector, High Energy Physics::Experiment, Nuclear Experiment, Production rate
Abstract: The inclusive production rate of phi mesons from the decay of b hadrons produced in Z0 decays was measured to be Br(b->phi+X) = 0.0282+-0.0013(stat.)+-0.0019(syst.), using data collected by the OPAL detector at LEP.
Published: 2000

26. Measurement of |Vcb| using decays

Author: G. Abbiendi, K. Ackerstaff, P.F. Akesson, G. Alexander, J. Allison, K.J. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, I. Bailey, A.H. Ball, E. Barberio, R.J. Barlow, J.R. Batley, S. Baumann, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, O. Biebel, A. Biguzzi, I.J. Bloodworth, P. Bock, J. Böhme, O. Boeriu, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, J. Cammin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, O.C. Cooke, J. Couchman, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, R. Davis, A. de Roeck, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, P.G. Estabrooks, E. Etzion, F. Fabbri, A. Fanfani, M. Fanti, A.A. Faust, L. Feld, P. Ferrari, F. Fiedler, M. Fierro, I. Fleck, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, C.K. Hargrove, M. Harin-Dirac, A. Hauke, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, C. Hensel, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, P.R. Hobson, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, T. Kobayashi, M. Kobel, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, M. Kupper, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, I. Lawson, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, J. Lillich, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Lu, J. Ludwig, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, T.E. Marchant, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, T.J. McMahon, R.A. McPherson, F. Meijers, P. Mendez-Lorenzo, F.S. Merritt, H. Mes, I. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Okpara, M.J. Oreglia, S. Orito, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, M. Przybycień, A. Quadt, C. Rembser, H. Rick, S.A. Robins, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, S. Tarem, R.J. Taylor, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. Torrence, S. Towers, T. Trefzger, I. Trigger, Z. Trócsányi, E. Tsur, M.F. Turner-Watson, I. Ueda, R. Van Kooten, P. Vannerem, M. Verzocchi, H. Voss, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Branching fraction, Form factor (quantum field theory), Zero (complex analysis), Value (computer science), 01 natural sciences, Recoil, 0103 physical sciences, Heavy quark effective theory, Matrix element, 010306 general physics
Abstract: The magnitude of the Cabibbo-Kobayashi-Maskawa matrix element Vcb has been measured using B0 to D*l nu decays recorded on the Z0 peak using the OPAL detector at LEP. The D* to D0 pi+ decays were reconstructed both in the particular decay modes D0 to K- pi+ and D0 to K- pi+ pi- and via an inclusive technique. The product of |Vcb| and the decay form factor of the B0 to D* l nu transition at zero recoil F(1) was measured to be F(1)|Vcb| = (37.1+-1.0+-2.0)x10^-3, where the uncertainties are statistical and systematic respectively. By using Heavy Quark Effective Theory calculations for F(1), a value of |Vcb| = (40.7+-1.1+-2.2+-1.6)x 10^-3 was obtained, where the third error is due to theoretical uncertainties in the value of F(1). The branching ratio Br(B0 to D* l nu) was also measured to be (5.26+-0.20+-0.46)%.
Published: 2000

27. Search for anomalous production of acoplanar di-lepton events in ${\rm e^+e^-}$ collisions at $\sqrt{s} =$ 183 and 189 GeV

Author: P. Ferrari, Randall Sobie, H. Mes, Naoko Kanaya, R. J. Hemingway, G. D. Lafferty, I. P. Duerdoth, S. Braibant, J. Lillich, Christopher Hawkes, German Martinez, K. Stephens, H. O. Ogren, B. W. Kennedy, P. Jovanovic, C. Littlewood, Christoph Geich-Gimbel, Gideon Bella, K. Stoll, Andris Skuja, S. Petzold, Austin Ball, Guenter Duckeck, A. A. Faust, P. Hüntemeyer, Daniel Lellouch, L. Brigliadori, H. J. Burckhart, Jacqueline Batley, Peter R Hobson, D. Zer-Zion, Takehiko Mori, Peter Krieger, Vakhtang Kartvelishvili, Tetsuro Mashimo, S. W. O'Neale, M. F. Turner-Watson, K. J. Anderson, Sachio Komamiya, A. Okpara, P. Mättig, T. J. McMahon, Richard Teuscher, R. Kowalewski, Erez Etzion, M. A. Thomson, A. T. Watson, Matthias Schröder, D. E. Plane, F. Fiedler, M. Thiergen, J. E. Conboy, A. Fürtjes, S. Arcelli, Alessandro Montanari, I. Meyer, C. Couyoumtzelis, T. P. Kokott, J. Dubbert, D. Waller, E. K. U. Gross, M. Verzocchi, W. Gorn, R. K. Carnegie, Shlomit Tarem, Lutz Feld, R. Van Kooten, T. Saeki, G. M. Dallavalle, Alessandra Fanfani, R. Davis, G. Gaycken, P. G. Bright-Thomas, J. A. Wilson, M. Sproston, C. R. Jones, J. Böhme, B. Surrow, M. Schumacher, M. Boutemeur, F. S. Merritt, Gideon Alexander, Thomas E Marchant, Paolo Capiluppi, Michael Hildreth, Achim Stahl, I. Trigger, Stefan Schmitt, Alain Bellerive, M. Kolrep, N. L. Rodning, T. Kuhl, Paul Kyberd, F. K. Loebinger, P. Dervan, S. Yamashita, P. Scharff-Hansen, B. Poli, F. Odorici, K. Graham, F. Wäckerle, D. R. Ward, Tara Shears, H. Voss, R. J. Barlow, Georges Azuelos, Ivor Fleck, Richard Nisius, B. List, Ekg Sarkisyan, D. M. Gingrich, P. Igo-Kemenes, E. Tsur, Ehud Duchovni, D. Axen, A. Jawahery, Oana Elena Vickey Boeriu, J. Grunhaus, J. Bechtluft, J. A. McKenna, D. J. Miller, Joleen Pater, K. W. Bell, J. Goldberg, Dave Charlton, Marco Cuffiani, K. Ishii, H. Jeremie, S. B. Anderson, Shoji Asai, M. Jimack, A. M. Smith, K. Hoffman, A. Klier, A. Michelini, Juergen Thomas, M. Przybycień, H. A. Neal, M. Fanti, T. Kress, J. C. Hill, J. M. Roney, S. Spagnolo, A. M. Rossi, W. R. Gibson, W. J. McDonald, B. C. Shen, A. A. Carter, I. J. Bloodworth, M. Donkers, Kiyotomo Kawagoe, K. Harder, Siegfried Bethke, D. Liu, A. K. Honma, Robert McPherson, Paolo Giacomelli, T. Kobayashi, Stan Bentvelsen, O. Schaile, M. Hansroul, Koichi Nagai, John Allison, W. G. Scott, J. Schieck, R. Hawkings, I. Nakamura, H. Landsman, Peter Sherwood, I. Cohen, R. D. Heuer, Christoph Rembser, James Pinfold, S. Robertson, Yoram Rozen, W. Mohr, Fabrizio Fabbri, A. Frey, R. Perez-Ochoa, R. Seuster, Giovanni Abbiendi, A. J. Martin, Claudia Ciocca, M. Harin-Dirac, S. A. Robins, R. L. Coxe, T. Trefzger, R. J. Homer, R. G. Kellogg, Junichi Kanzaki, J. Polok, R. M. Brown, D. Karlen, D. R. Rust, P. Mendez-Lorenzo, F. G. Oakham, R. Liebisch, K. Ackerstaff, Alexander Wagner, A. Macchiolo, J. Ludwig, A. Hocker, Daniele Bonacorsi, K. Runge, P. Bock, Lorne Levinson, Csaba Hajdu, D. Glenzinski, Dezso Horvath, M. J. Losty, Stefano Marcellini, E. L. Barberio, D. Chrisman, G. D. Long, V. Zacek, K. R. Hossain, W. M. Sang, J. Couchman, W. Mader, O. C. Cooke, P. Pfeifenschneider, J. W. Gary, Marcello Mannelli, C. K. Hargrove, Stephen Lloyd, J. Patt, D. C. Imrie, André Schöning, C. H. Shepherd-Themistocleous, J. von Krogh, O. Sahr, C. Sbarra, F. R. Jacob, G. P. Siroli, M. Gruwé, D. Wetterling, Christoph Schwick, K. Roscoe, P. Gagnon, S. Baumann, E. Torrence, Zoltan Laszlo Trocsanyi, E. Clay, Dong Hee Kim, J. Lauber, E. A. Mckigney, S. D. Talbot, T. Behnke, Satoshi Mihara, T. R. Junk, D. Lanske, D. I. Futyan, P. S. Wells, Terry Richard Wyatt, O. Runolfsson, P. G. Estabrooks, R. K. Keeler, N. K. Watson, Arnulf Quadt, P. M. Watkins, Claudio Grandi, J. S. White, M. Fierro, S. Rosati, A. Harel, Ikuo Ueda, D. M. Strom, A. D. Schaile, Gabriella Pasztor, J. Lu, P. Vannerem, G. A. Snow, C. P. Ward, Raimund Ströhmer, S. Söldner-Rembold, P. Poffenberger, Beatrix Dienes, J. Letts, C. Y. Chang, P. Taras, A. Macpherson, K. Sachs, Shlomo Dado, Giora Mikenberg, Klaus Desch, S. F. Ashby, R. Howard, Otmar Biebel, P. I. Kayal, Norbert Wermes, Sherry Towers, T. Kawamoto, S. Orito, S. Betts, M. Hapke, M. J. Oreglia, Gregor Herten, J. E. Pilcher, A. W. Lloyd, G. W. Wilson, M. Hauschild, S.J. Dallison, J. R. Carter, G. N. Patrick, A. Biguzzi, J. G. Layter, P. E.L. Clarke, J. P. Martin, S. De Jong, H. Rick, G. G. Hanson, G. Giacomelli, I. Lawson, A. De Roeck, M. Kobel, M. S. Dixit, and Frans Meijers
Subjects: Physics, Particle physics, Physics and Astronomy (miscellaneous), Branching fraction, Electron–positron annihilation, High Energy Physics::Phenomenology, Standard Model, Nuclear physics, Chargino, Neutralino, Higgs boson, High Energy Physics::Experiment, Nuclear Experiment, Engineering (miscellaneous), Minimal Supersymmetric Standard Model, Lepton
Abstract: A selection of di-lepton events with significant missing transverse momentum has been performed using a total data sample of 237.4 pb-1 at e+e- centre-of-rnass energies of approximately 183 GeV and 189 GeV. The observed numbers of events - 78 at 183 GeV and 301 at 189 GeV - are consistent with the numbers expected from Standard Model processes, which arise predominantly from W+W- production with both W bosons decaying leptonically. This topology is also an experimental signature for the pair production of new particles that decay to a charged lepton accompanied by one or more invisible particles. Discrimination techniques are described that optimise the sensitivity to particular new physics channels. No evidence for new phenomena is apparent. Upper limits on the production cross-section times branching ratio squared for sleptons and for leptonically decaying charginos and charged Higgs are presented in a manner intended to minimise the number of model assumptions. Assuming a 100% branching ratio for the decay l±R → l±χ01, where χ01 is the lightest neutralino, we exclude at 95% CL: right-handed smuons with masses below 82.3 GeV for mμ- - mχ01 > 3 GeV and right-handed staus with masses below 81.0 GeV for mτ- -mχ01 > 8 GeV. Right-handed selectrons are excluded at 95% CL for masses below 87.1 GeV for mẽ - mχ01 > 5 GeV, within the framework of the Minimal Supersymmetric Standard Model assuming μ, < - 100 GeV and tan β= 1.5. Charged Higgs bosons, H±, are excluded at 95% CL for masses below 82.8 GeV, assuming a 100% branching ratio for the decay H± → τ ± vτ.
Published: 2000

28. A study of parton fragmentation in hadronic Z $^0$ decays using $\Lambda\bar\Lambda$ correlations

Author: B. Nellen, H. G. Evans, I. Cohen, Tara Shears, Christoph Rembser, C. Hartmann, D. E. Plane, T. J. McMahon, C. Couyoumtzelis, Stephen Hillier, G. Gaycken, P. G. Bright-Thomas, J. Dubbert, G. M. Dallavalle, S. A. Robins, R. K. Carnegie, M. Schumacher, M. Herndon, M. Bobinski, R. Liebisch, K. Stoll, P. G. Estabrooks, R. K. Keeler, J. A. Wilson, J. Böhme, Andris Skuja, K. Ackerstaff, Matthias Schröder, M. Thiergen, Gregor Herten, N. K. Watson, Dave Charlton, S. Petzold, P. M. Watkins, D. Lazic, A. Macpherson, M. Fierro, Randall Sobie, G. D. Lafferty, A. J. Martin, F. Odorici, Tetsuro Mashimo, S. R. Lautenschlager, J. Grunhaus, W. Mader, Erez Etzion, C. K. Hargrove, S. Betts, M. Hapke, S. Yamashita, J. E. Pilcher, Stefan Kluth, Shlomit Tarem, Stefan Schmitt, K. Roscoe, H. A. Neal, R. Bürgin, B. Surrow, C. Y. Chang, D. R. Rust, A. W. Lloyd, P. Igo-Kemenes, Georges Azuelos, P. E.L. Clarke, O. Runolfsson, A. D. Schaile, Gabriella Pasztor, E. Tsur, P. Vannerem, M. J. Oreglia, Klaus Kurt Desch, G. W. Wilson, W. Gorn, K. Ishii, H. Jeremie, M. Hauschild, C. Markopoulos, John Allison, J. Lauber, G. Yekutieli, S. Baumann, M. Przybycień, Guenter Duckeck, Sachio Komamiya, A. T. Watson, A. A. Carter, R. Howard, M. Verzocchi, K. W. Bell, P. Taras, Ron Folman, A. M. Lee, E. von Törne, E. A. Mckigney, E. Torrence, Claudio Grandi, J. S. White, J. Pálinkás, T. P. Kokott, G. A. Snow, C. P. Ward, J. P. Martin, J. R. Carter, S. Söldner-Rembold, G. N. Patrick, R. Mir, R. Hawkings, Otmar Biebel, E. Clay, Shoji Asai, Gideon Bella, Ekg Sarkisyan, T. Saeki, R. Davis, J. C. Hill, J. Letts, M. Fanti, O. Schaile, H. J. Burckhart, Daniel Lellouch, D. I. Futyan, Jacqueline Batley, P. I. Kayal, Takehiko Mori, H. Mes, James Pinfold, R. Perez-Ochoa, R. Seuster, Giovanni Abbiendi, S. De Jong, Claire Shepherd-Themistocleous, S. Robertson, Daniele Bonacorsi, S. B. Anderson, K. Sachs, Shlomo Dado, I. P. Duerdoth, S. Braibant, Norbert Wermes, Sherry Towers, T. Kawamoto, W. J. McDonald, W. R. Gibson, B. C. Shen, Robert McPherson, M. Boutemeur, F. S. Merritt, D. M. Strom, P. Mättig, J. Gascon, S. Orito, K. Harder, F. G. Oakham, B. Schmitt, E. L. Barberio, R. E. Schmitz, R. D. Heuer, Fabrizio Fabbri, Sven Menke, D. Lanske, Siegfried Bethke, D. Liu, Giora Mikenberg, S. F. Ashby, H. Rick, V. Zacek, R. Van Kooten, Stan Bentvelsen, J. von Krogh, P. Hüntemeyer, Raimund Ströhmer, R. J. Hemingway, A. A. Faust, A. K. Honma, W. G. Scott, S. D. Talbot, J. W. Gary, C. R. Jones, D. S. Koetke, R. M. Brown, Lorne Levinson, M. F. Turner-Watson, M. Gruwé, L. A. del Pozo, Marcello Mannelli, Peter R Hobson, I. Nakamura, B. W. Kennedy, P. Jovanovic, D. M. Gingrich, P. Scharff-Hansen, J. Bechtluft, Richard Teuscher, I. J. Bloodworth, D. Zer-Zion, A. S. Turcot, F. Fiedler, P. Poffenberger, J. A. McKenna, T. R. Junk, D. Eatough, Austin Ball, Peter Krieger, A. Macchiolo, A. M. Smith, P. S. Wells, D. Glenzinski, Dezso Horvath, M. J. Losty, R. G. Kellogg, G. G. Hanson, Jean-Arcady Meyer, Terry Richard Wyatt, C. M. Hawkes, Yoram Rozen, M. Kolrep, T. Behnke, R. Bartoldus, Alessandro Montanari, T. Kuhl, H. O. Ogren, J. Polok, G. Giacomelli, I. Lawson, Richard Nisius, Christoph Geich-Gimbel, D. Karlen, A. De Roeck, M. Kobel, O. C. Cooke, Beatrix Dienes, B. List, Marco Cuffiani, P. Pfeifenschneider, M. S. Dixit, Frans Meijers, Vakhtang Kartvelishvili, J. E. Conboy, A. Fürtjes, P. Gagnon, Stefano Marcellini, L. Brigliadori, N. Altekamp, H. Voss, R. J. Barlow, A. Biguzzi, D. J. Miller, J. Patt, J. G. Layter, A. Sittler, Zoltan Laszlo Trocsanyi, André Schöning, O. Sahr, W. M. Sang, S. W. O'Neale, K. J. Anderson, S. D. Bird, D. Axen, A. Jawahery, Peter Sherwood, Alexander Wagner, J. Ludwig, K. Runge, P. Bock, Paolo Giacomelli, C. Sbarra, F. R. Jacob, M. Hansroul, Paul Kyberd, F. K. Loebinger, J. Steuerer, Ivor Fleck, C. Burgard, Joleen Pater, A. Klier, R. J. Homer, Satoshi Mihara, Kiyotomo Kawagoe, Achim Stahl, K. R. Hossain, D. C. Imrie, G. P. Siroli, K. Stephens, Christoph Schwick, C. Littlewood, V. Gibson, I. Trigger, F. Scharf, German Martinez, D. R. Ward, T. Kress, J. M. Roney, Ehud Duchovni, Koichi Nagai, J. Schieck, W. Mohr, M. Jimack, M. A. Thomson, A. Michelini, Claudia Ciocca, F. Wöckerle, E. K. U. Gross, M. Sproston, S. M. Gascon-Shotkin, Satoshi Tanaka, T. Kobayashi, A. M. Rossi, R. L. Coxe, A. Hocker, D. Chrisman, G. D. Long, Volker Blobel, Michael Hildreth, Alain Bellerive, Stephen Lloyd, N. L. Rodning, R. Kowalewski, S. Arcelli, Gideon Alexander, Paolo Capiluppi, and J. Goldberg
Subjects: Physics, Particle physics, Physics and Astronomy (miscellaneous), Electron–positron annihilation, Hadron, Hyperon, Parton, Lambda, Lambda baryon, Nuclear physics, Baryon, High Energy Physics::Experiment, Rapidity, Engineering (miscellaneous)
Abstract: The correlated production of $\Lambda$ and $\bar\Lambda$ baryons has been studied using 4.3 million multihadronic ${\rm Z}^0$ decays recorded with the Opal detector at Lep. Lambda pairs were investigated in the full data sample and for the first time also in 2-jet and 3-jet events selected with the $k_\perp$ algorithm. The distributions of rapidity differences from correlated $\Lambda\bar\Lambda$ pairs exhibit short-range, local correlations and prove to be a sensitive tool to test models, particularly for 2-jet events. The Jetset model describes the data best but some extra parameter tuning is needed to improve agreement with the experimental results in the rates and the rapidity spectra simultaneously. The recently developed modification of Jetset, the MOdified Popcorn Scenarium (Mops), and also Herwig do not give satisfactory results. This study of di-lambda production in 2- and 3-jet events supports the short-range compensation of quantum numbers.
Published: 2000

29. Z boson pair production in e+e− collisions at and 189 GeV

Author: G. Abbiendi, K. Ackerstaff, P.F. Akesson, G. Alexander, J. Allison, K.J. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, I. Bailey, A.H. Ball, E. Barberio, R.J. Barlow, J.R. Batley, S. Baumann, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, O. Biebel, A. Biguzzi, I.J. Bloodworth, P. Bock, J. Böhme, O. Boeriu, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, J. Cammin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, O.C. Cooke, J. Couchman, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, S. Dallison, R. Davis, A. de Roeck, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, M. Donkers, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, P.G. Estabrooks, E. Etzion, F. Fabbri, A. Fanfani, M. Fanti, A.A. Faust, L. Feld, P. Ferrari, F. Fiedler, M. Fierro, I. Fleck, A. Frey, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, P.O. Günther, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, C.K. Hargrove, M. Harin-Dirac, A. Hauke, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, C. Hensel, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, P.R. Hobson, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, N. Kanaya, J. Kanzaki, G. Karapetian, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, K. Klein, A. Klier, T. Kobayashi, M. Kobel, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, M. Kupper, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, I. Lawson, J.G. Layter, A. Leins, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, J. Lillich, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Lu, J. Ludwig, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, T.E. Marchant, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, T.J. McMahon, R.A. McPherson, F. Meijers, P. Mendez-Lorenzo, F.S. Merritt, H. Mes, I. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Okpara, M.J. Oreglia, S. Orito, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, B. Poli, J. Polok, M. Przybycień, A. Quadt, C. Rembser, H. Rick, S.A. Robins, N. Rodning, J.M. Roney, S. Rosati, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, P. Scharff-Hansen, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, S. Tarem, R.J. Taylor, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. Torrence, S. Towers, T. Trefzger, I. Trigger, Z. Trócsányi, E. Tsur, M.F. Turner-Watson, I. Ueda, R. Van Kooten, P. Vannerem, M. Verzocchi, H. Voss, D. Waller, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, T. Wengler, N. Wermes, D. Wetterling, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, V. Zacek, and D. Zer-Zion
Subjects: Quark, Physics, Nuclear and High Energy Physics, Particle physics, Annihilation, 010308 nuclear & particles physics, State (functional analysis), 01 natural sciences, Standard Model, Pair production, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010303 astronomy & astrophysics, Lepton
Abstract: A study of Z boson pair production in e+e- annihilation at center-of-mass energies near 183 GeV and 189 GeV is reported. Final states containing only leptons, (l+l-l+l- and l+l-nu nubar), quark and lepton pairs, (q qbar l+l-, q qbar nu nubar) and the all-hadronic final state (q qbar q qbar) are considered. In all states with at least one Z boson decaying hadronically, q qbar and b bbar final states are considered separately using lifetime and event-shape tags, thereby improving the cross-section measurement. At sqrt(s) = 189 GeV the Z-pair cross section was measured to be 0.80 (+0.14-0.13, stat.) (+0.06-0.05, syst.) pb, consistent with the Standard Model prediction. At sqrt(s) = 183 GeV the 95% C.L. upper limit is 0.55 pb. Limits on anomalous ZZgamma and ZZZ couplings are derived.
Published: 2000

30. Neutron response functions for superheated droplet detectors

Author: V. Zacek, L. Lessard, and Louis-Andre Hamel
Subjects: Physics, Nuclear and High Energy Physics, Fabrication, Physics::Instrumentation and Detectors, Nuclear Theory, Detector, Threshold function, Particle detector, Superheating, Nuclear physics, Nuclear Energy and Engineering, Measuring instrument, Neutron detection, Neutron, Electrical and Electronic Engineering, Nuclear Experiment
Abstract: Neutron response functions for superheated droplet detectors have been analyzed from threshold up to 2 MeV incident energy, taking into account a gradual threshold function, in terms of temperature and incident energy. A method for obtaining fitted parameters is described. Detection mechanisms up to 14 MeV are discussed.
Published: 1999

31. A study of $\mathrm{B_s^0}$ meson oscillation using hadronic $\mathrm Z^0$ decays containing leptons

Author: H. O. Ogren, Erez Etzion, Christoph Geich-Gimbel, Shlomit Tarem, Sachio Komamiya, D. Axen, S. Yamashita, A. T. Watson, A. Jawahery, B. Surrow, Richard Teuscher, P. Igo-Kemenes, Vakhtang Kartvelishvili, F. Fiedler, A. Biguzzi, J. E. Conboy, A. Fürtjes, J. G. Layter, K. Ishii, H. Jeremie, Peter Sherwood, Daniele Bonacorsi, J. von Krogh, M. Gruwé, D. Wetterling, T. P. Kokott, T. Saeki, Lutz Feld, Kiyotomo Kawagoe, O. C. Cooke, Alexander Wagner, A. Macchiolo, W. R. Gibson, P. Pfeifenschneider, T. J. McMahon, C. Couyoumtzelis, S. Betts, A. Macpherson, J. Dubbert, J. Ludwig, M. Hapke, K. Harder, S. A. Robins, R. Liebisch, K. Ackerstaff, J. Letts, R. K. Carnegie, G. Gaycken, P. G. Bright-Thomas, J. A. Wilson, J. Böhme, Raimund Ströhmer, M. Kolrep, Alessandra Fanfani, R. Davis, S. Baumann, K. Runge, P. Bock, M. Przybycień, T. Kress, E. A. Mckigney, A. A. Carter, I. J. Bloodworth, J. Patt, André Schöning, O. Schaile, W. J. McDonald, Giovanni Abbiendi, M. Schumacher, Matthias Schröder, B. C. Shen, R. J. Hemingway, M. A. Thomson, J. Lauber, M. Boutemeur, F. S. Merritt, O. Sahr, Klaus Desch, P. E.L. Clarke, R. Howard, S. Robertson, P. Poffenberger, Siegfried Bethke, D. Liu, A. K. Honma, K. R. Hossain, C. H. Shepherd-Themistocleous, K. Sachs, Christopher Hawkes, W. M. Sang, S. B. Anderson, Shlomo Dado, J. Grunhaus, E. K. U. Gross, R. L. Coxe, M. Thiergen, F. Odorici, W. G. Scott, Yoram Rozen, J. P. Martin, B. W. Kennedy, T. Kuhl, S. De Jong, I. Nakamura, Richard Nisius, J. Goldberg, J. Bechtluft, M. Sproston, P. Jovanovic, M. J. Oreglia, Stan Bentvelsen, Austin Ball, K. Stoll, S. D. Talbot, R. M. Brown, Lorne Levinson, Andris Skuja, Peter Krieger, B. List, H. Rick, Marco Cuffiani, P. Mendez-Lorenzo, Junichi Kanzaki, J. Polok, D. I. Futyan, Gregor Herten, K. Hoffman, Giora Mikenberg, S. F. Ashby, D. Glenzinski, Paolo Giacomelli, D. Karlen, T. Behnke, R. D. Heuer, Alessandro Montanari, Daniel Lellouch, T. R. Junk, P. S. Wells, M. Hansroul, Beatrix Dienes, A. Hocker, J. A. McKenna, I. Cohen, S. Petzold, Juergen Thomas, Tetsuro Mashimo, M. F. Turner-Watson, A. D. Schaile, Randall Sobie, G. D. Lafferty, R. Hawkings, Christoph Rembser, Dezso Horvath, M. J. Losty, Takehiko Mori, A. Okpara, Terry Richard Wyatt, P. Mättig, G. D. Long, G. G. Hanson, C. Y. Chang, Gabriella Pasztor, P. Gagnon, H. Landsman, J. M. Roney, M. Verzocchi, J. E. Pilcher, H. Mes, P. G. Estabrooks, R. K. Keeler, N. K. Watson, M. Harin-Dirac, P. Vannerem, G. A. Snow, C. P. Ward, D. C. Imrie, R. J. Homer, G. Giacomelli, I. Lawson, A. De Roeck, M. Kobel, Arnulf Quadt, Naoko Kanaya, P. M. Watkins, Guenter Duckeck, A. Sittler, Zoltan Laszlo Trocsanyi, I. P. Duerdoth, S. Braibant, F. G. Oakham, P. Taras, Dong Hee Kim, Koichi Nagai, J. Schieck, C. Sbarra, F. R. Jacob, Stefan Schmitt, G. P. Siroli, S. Söldner-Rembold, W. Gorn, J. R. Carter, G. N. Patrick, E. L. Barberio, A. J. Martin, M. S. Dixit, Stephen Lloyd, Frans Meijers, Satoshi Mihara, P. Hüntemeyer, Christoph Schwick, K. Roscoe, W. Mohr, John Allison, Otmar Biebel, Georges Azuelos, E. Tsur, Shoji Asai, P. Scharff-Hansen, A. A. Faust, Achim Stahl, O. Runolfsson, K. W. Bell, N. Altekamp, H. Voss, A. W. Lloyd, E. Torrence, R. J. Barlow, D. J. Miller, J. Couchman, W. Mader, Ehud Duchovni, A. M. Smith, R. G. Kellogg, K. Stephens, J. C. Hill, E. Clay, C. K. Hargrove, K. Graham, G. W. Wilson, M. Jimack, Csaba Hajdu, S. Spagnolo, C. Littlewood, Tara Shears, P. I. Kayal, Claudio Grandi, J. S. White, Stefano Marcellini, M. Hauschild, German Martinez, Ekg Sarkisyan, James Pinfold, L. Brigliadori, R. Perez-Ochoa, R. Seuster, V. Gibson, A. Michelini, Norbert Wermes, Sherry Towers, D. E. Plane, T. Kawamoto, D. Lanske, V. Zacek, Paul Kyberd, F. K. Loebinger, I. Trigger, T. Kobayashi, J. W. Gary, J. Steuerer, Ivor Fleck, D. R. Ward, S. Orito, G. M. Dallavalle, Marcello Mannelli, Joleen Pater, A. Klier, H. A. Neal, M. Fierro, R. Kowalewski, S. W. O'Neale, S. Arcelli, K. J. Anderson, Gideon Alexander, Paolo Capiluppi, Gideon Bella, H. J. Burckhart, Jacqueline Batley, C. R. Jones, M. Fanti, Peter R Hobson, D. Zer-Zion, Robert McPherson, Fabrizio Fabbri, A. Frey, R. Van Kooten, Claudia Ciocca, F. Wäckerle, D. M. Gingrich, A. M. Rossi, Michael Hildreth, Alain Bellerive, N. L. Rodning, P. Dervan, B. Poli, D. R. Rust, S. Rosati, A. Harel, Ikuo Ueda, D. M. Strom, and J. Lu
Subjects: Physics, Particle physics, Physics and Astronomy (miscellaneous), Meson, Oscillation, Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, Charge (physics), Jet (particle physics), Nuclear physics, High Energy Physics::Experiment, Production (computer science), Engineering (miscellaneous), Lepton
Abstract: A sample of ${\rm Z}^0$ decays containing b-flavoured hadrons is tagged using leptons, and events having precise proper time measurements are selected. These events are used to study ${\rm B}^0_{\rm s}$ oscillations. The flavour (b or $\rm \bar{b}$) at decay is determined from the lepton charge while the flavour at production is determined from jet charge or the charge of a second lepton, where available. The experiment was not able to resolve the oscillatory behaviour, and we deduce that the ${\rm B}^0_{\rm s}$ oscillation frequency $\Delta m_{\rm s} > 5.2$ ps$^{-1}$ at the 95% confidence level.
Published: 1999

32. Intermittency and correlations in hadronic Z $^0$ decays

Author: K. Stephens, M. Schumacher, P. G. Estabrooks, F. Odorici, N. K. Watson, D. R. Rust, C. Littlewood, H. A. Neal, Otmar Biebel, P. Scharff-Hansen, P. M. Watkins, K. Hoffman, V. Gibson, Claire Shepherd-Themistocleous, A. M. Lee, J. Goldberg, Erez Etzion, Shlomit Tarem, B. Surrow, G. G. Hanson, Richard Teuscher, A. S. Turcot, N. Altekamp, H. Voss, A. Macpherson, H. O. Ogren, Christoph Geich-Gimbel, I. Trigger, F. Fiedler, Richard Keeler, D. R. Ward, A. M. Smith, P. I. Kayal, K. Stoll, G. Giacomelli, S. Yamashita, I. Lawson, R. J. Barlow, D. J. Miller, I. Cohen, Christoph Rembser, H. Mes, I. P. Duerdoth, S. Braibant, D. Axen, A. Jawahery, T. J. McMahon, A. De Roeck, M. Kobel, P. Igo-Kemenes, M. Hoch, K. Ishii, H. Jeremie, Dave Charlton, C. Couyoumtzelis, M. Fanti, S. A. Robins, M. S. Dixit, O. C. Cooke, S. Spagnolo, Andris Skuja, S. Petzold, Tetsuro Mashimo, A. A. Faust, Peter Sherwood, Alexander Wagner, R. Liebisch, K. Ackerstaff, Norbert Wermes, Sherry Towers, T. Kawamoto, Frans Meijers, J. Dubbert, P. Pfeifenschneider, M. F. Turner-Watson, I. J. Bloodworth, Vakhtang Kartvelishvili, P. Hüntemeyer, R. K. Carnegie, A. J. Martin, R. Kowalewski, J. E. Conboy, A. Fürtjes, R. Howard, P. E.L. Clarke, J. Ludwig, K. Runge, R. Mir, P. Bock, M. Kolrep, J. Patt, R. Hawkings, Satoshi Mihara, Paul Kyberd, S. Orito, S. Arcelli, M. Herndon, F. K. Loebinger, S. Baumann, J. A. Wilson, J. Böhme, Michael Hildreth, Alain Bellerive, André Schöning, Robert McPherson, J. P. Martin, O. Sahr, H. Landsman, P. Gagnon, J. Steuerer, Ivor Fleck, O. Schaile, S. Robertson, R. D. Heuer, E. A. Mckigney, Gideon Alexander, N. L. Rodning, W. Gorn, W. Mader, Paolo Capiluppi, Joleen Pater, P. Dervan, B. Poli, Peter R Hobson, S. De Jong, A. Klier, F. G. Oakham, A. Sittler, D. Zer-Zion, D. C. Imrie, C. K. Hargrove, S. Betts, Yoram Rozen, S. B. Anderson, Matthias Schröder, W. R. Gibson, Gregor Herten, R. L. Coxe, Georges Azuelos, K. Harder, Fabrizio Fabbri, A. Frey, H. Rick, E. L. Barberio, D. Lazic, A. Macchiolo, Zoltan Laszlo Trocsanyi, Dong Hee Kim, M. Hapke, A. Hocker, M. Thiergen, Gideon Bella, H. J. Burckhart, Jacqueline Batley, D. Chrisman, G. D. Long, E. Tsur, D. I. Futyan, Volker Blobel, R. J. Hemingway, T. Kuhl, J. Lauber, R. Van Kooten, S. M. Gascon-Shotkin, Paolo Giacomelli, Sven Menke, Christopher Hawkes, G. Yekutieli, M. Verzocchi, K. W. Bell, J. Pálinkás, J. Grunhaus, G. P. Siroli, M. Przybycień, Junichi Kanzaki, J. Polok, M. Boutemeur, F. S. Merritt, B. W. Kennedy, W. M. Sang, P. Jovanovic, Richard Nisius, D. Karlen, M. Hansroul, S. D. Talbot, Stan Bentvelsen, Christoph Schwick, T. Kress, M. J. Oreglia, J. E. Pilcher, Stephen Lloyd, Austin Ball, J. C. Hill, T. R. Junk, K. Graham, A. A. Carter, Ron Folman, P. S. Wells, B. List, Peter Krieger, Marco Cuffiani, Tara Shears, R. M. Brown, Ehud Duchovni, Lorne Levinson, Alessandro Montanari, W. J. McDonald, M. Jimack, B. C. Shen, A. M. Rossi, A. Biguzzi, J. G. Layter, F. Wäckerle, Terry Richard Wyatt, D. M. Gingrich, Randall Sobie, G. D. Lafferty, Giovanni Abbiendi, A. Michelini, J. R. Carter, C. R. Jones, Siegfried Bethke, D. Liu, A. K. Honma, W. G. Scott, T. Kobayashi, Juergen Thomas, J. Bechtluft, J. A. McKenna, Stefan Schmitt, G. N. Patrick, Daniele Bonacorsi, I. Nakamura, S. Rosati, R. J. Homer, C. Sbarra, F. R. Jacob, Sachio Komamiya, A. T. Watson, A. Harel, Ikuo Ueda, D. M. Strom, J. von Krogh, Guenter Duckeck, D. Glenzinski, J. Lu, Dezso Horvath, M. J. Losty, John Allison, T. P. Kokott, T. Saeki, Claudia Ciocca, K. Roscoe, Jean-Arcady Meyer, Klaus Kurt Desch, M. Gruwé, Shoji Asai, Alessandra Fanfani, R. Davis, E. Torrence, E. Clay, Achim Stahl, R. G. Kellogg, Daniel Lellouch, T. Behnke, Stefano Marcellini, A. W. Lloyd, Kiyotomo Kawagoe, G. W. Wilson, Takehiko Mori, D. E. Plane, P. Mättig, M. Hauschild, C. Markopoulos, G. M. Dallavalle, K. R. Hossain, James Pinfold, R. Perez-Ochoa, R. Seuster, J. Gascon, V. Zacek, M. A. Thomson, J. W. Gary, L. Brigliadori, Ekg Sarkisyan, E. K. U. Gross, Marcello Mannelli, M. Sproston, S. W. O'Neale, K. J. Anderson, Raimund Ströhmer, J. Letts, P. Poffenberger, German Martinez, Beatrix Dienes, J. M. Roney, C. Y. Chang, P. Taras, D. Lanske, Koichi Nagai, J. Schieck, W. Mohr, M. Fierro, S. R. Lautenschlager, K. Sachs, O. Runolfsson, Shlomo Dado, Claudio Grandi, J. S. White, Giora Mikenberg, S. F. Ashby, A. D. Schaile, Gabriella Pasztor, P. Vannerem, G. A. Snow, C. P. Ward, S. Söldner-Rembold, G. Gaycken, and P. G. Bright-Thomas
Subjects: Physics, Quantum chromodynamics, Particle physics, Annihilation, Physics and Astronomy (miscellaneous), Hadron, Monte Carlo method, Fizikai tudományok, Multiplicity (mathematics), Bose–Einstein correlations, law.invention, Nuclear physics, Természettudományok, law, Intermittency, High Energy Physics::Experiment, Engineering (miscellaneous), Cumulant, Particle Physics - Experiment
Abstract: A multidimensional study of local multiplicity fluctuations and multiparticle correlations of hadrons produced in Z decays is performed. The study is based on the data sample of more than 4 million events recorded with the OPAL detector at LEP. The fluctuations and correlations are analysed in terms of the normalized scaled factorial moments and cumulants up to the fifth order. The moments are observed to have intermittency-like behaviour, which is found to be more pronounced with increasing dimension. The large data sample allows for the first time a study of the factorial cumulants in e+e- annihilation. The analysis of the cumulants shows the existence of genuine multiparticle correlations with a strong intermittency rise up to higher orders. These correlations are found to be stronger in higher dimensions. The decomposition of the factorial moments into lower-order correlations that the dynamical fluctuations have important contributions from genuine many-particle correlations. The Monte Carlo models JETSET 7.4 and HERWIG 5.9 are found to reproduce the trend of the measured moments and cumulants but they underestimate the magnitudes. The results are found to be consistent with QCD jet formation dynamics, although additional contributions from other mechanisms in the hadronization process cannot be excluded. A multidimensional study of local multiplicity fluctuations and multiparticle correlations of hadrons produced in Z decays is performed. The study is based on the data sample of more than 4 million events recorded with the OPAL detector at LEP. The fluctuations and correlations are analysed in terms of the normalized scaled factorial moments and cumulants up to the fifth order. The moments are observed to have intermittency-like behaviour, which is found to be more pronounced with increasing dimension. The large data sample allows for the first time a study of the factorial cumulants in e+e- annihilation. The analysis of the cumulants shows the existence of genuine multiparticle correlations with a strong intermittency rise up to higher orders. These correlations are found to be stronger in higher dimensions. The decomposition of the factorial moments into lower-order correlations shows that the dynamical fluctuations have important contributions from genuine many-particle correlations. The Monte Carlo models JETSET 7.4 and HERWIG 5.9 are found to reproduce the trend of the measured moments and cumulants but they underestimate the magnitudes. The results are found to be consistent with QCD jet formation dynamics, although additional contributions from other mechanisms in the hadronization process cannot be excluded.
Published: 1999

33. A measurement of the product branching ratio $f ({\rm b} \to \Lambda_{\rm b}) \cdot{\rm BR} (\Lambda_{\rm b} \to \Lambda {\rm X})$ in ${\rm Z}^0$ decays

Author: Raimund Ströhmer, A. Harel, Ikuo Ueda, D. M. Strom, P. G. Estabrooks, R. K. Keeler, P. Poffenberger, Dave Charlton, N. K. Watson, Michael Hildreth, Sachio Komamiya, Alain Bellerive, A. T. Watson, Claire Shepherd-Themistocleous, N. L. Rodning, P. Dervan, Otmar Biebel, F. Scharf, German Martinez, W. M. Sang, Beatrix Dienes, P. M. Watkins, S. Yamashita, A. Macpherson, R. D. Heuer, T. P. Kokott, S. M. Gascon-Shotkin, P. Igo-Kemenes, M. Hoch, K. Ishii, H. Jeremie, T. J. McMahon, C. Couyoumtzelis, T. Saeki, Gideon Bella, Achim Stahl, R. Howard, T. R. Junk, J. Dubbert, P. S. Wells, R. Davis, Terry Richard Wyatt, A. M. Rossi, R. K. Carnegie, H. J. Burckhart, Jacqueline Batley, P. I. Kayal, M. Herndon, A. A. Faust, O. Schaile, R. L. Coxe, D. R. Rust, J. A. Wilson, J. Böhme, J. Lauber, C. Sbarra, Norbert Wermes, F. R. Jacob, J. Grunhaus, Sherry Towers, T. Kawamoto, S. Robertson, L. Brigliadori, M. A. Thomson, M. Boutemeur, F. S. Merritt, H. Mes, A. Hocker, E. K. U. Gross, D. Lazic, I. P. Duerdoth, S. Braibant, C. R. Jones, S. Orito, Sven Menke, O. C. Cooke, A. M. Lee, John Allison, E. von Törne, M. Sproston, D. Chrisman, G. D. Long, Volker Blobel, P. Pfeifenschneider, Kiyotomo Kawagoe, Claudia Ciocca, A. W. Lloyd, Juergen Thomas, G. W. Wilson, S. R. Lautenschlager, G. Yekutieli, J. Patt, André Schöning, P. Hüntemeyer, M. Przybycień, Stephen Lloyd, T. Kress, R. G. Kellogg, O. Sahr, J. Bechtluft, M. Fanti, A. A. Carter, S. W. O'Neale, J. A. McKenna, Ron Folman, M. Hauschild, C. Markopoulos, K. J. Anderson, Stefano Marcellini, R. Mir, R. Hawkings, O. Runolfsson, J. M. Roney, S. D. Talbot, Ehud Duchovni, C. Y. Chang, Robert McPherson, G. Gaycken, P. G. Bright-Thomas, Paul Kyberd, Giovanni Abbiendi, F. K. Loebinger, Peter R Hobson, M. Jimack, H. Landsman, Koichi Nagai, Paolo Giacomelli, Claudio Grandi, D. Zer-Zion, R. Bartoldus, M. Hansroul, J. Schieck, H. O. Ogren, M. Schumacher, Fabrizio Fabbri, P. Taras, W. Mohr, J. Steuerer, Ivor Fleck, A. Michelini, A. Macchiolo, J. S. White, Ekg Sarkisyan, K. Stephens, Joleen Pater, J. Letts, A. Klier, Christoph Geich-Gimbel, F. Odorici, S. Baumann, Daniele Bonacorsi, R. Van Kooten, E. A. Mckigney, C. Hartmann, D. E. Plane, C. Littlewood, D. Eatough, Satoshi Tanaka, H. A. Neal, T. Kobayashi, R. J. Homer, T. Behnke, V. Gibson, K. R. Hossain, Vakhtang Kartvelishvili, F. G. Oakham, J. von Krogh, T. Kuhl, B. Schmitt, K. Hoffman, E. L. Barberio, G. M. Dallavalle, F. Wäckerle, D. M. Gingrich, J. E. Conboy, A. Fürtjes, Stefan Schmitt, M. Gruwé, I. Trigger, D. R. Ward, Richard Nisius, D. Lanske, B. List, D. C. Imrie, Gregor Herten, N. Altekamp, H. Voss, R. Kowalewski, Satoshi Mihara, S. Arcelli, R. J. Barlow, D. J. Miller, K. Roscoe, J. E. Pilcher, Marco Cuffiani, P. Gagnon, Gideon Alexander, S. Spagnolo, Klaus Kurt Desch, D. I. Futyan, Paolo Capiluppi, G. P. Siroli, M. Fierro, R. J. Hemingway, E. Torrence, E. Clay, K. Sachs, Christoph Schwick, Christopher Hawkes, B. W. Kennedy, P. Jovanovic, Austin Ball, Peter Krieger, Alessandro Montanari, C. Darling, W. R. Gibson, K. Harder, W. J. McDonald, B. C. Shen, A. Sittler, Zoltan Laszlo Trocsanyi, Shlomo Dado, Dong Hee Kim, R. M. Brown, Lorne Levinson, Siegfried Bethke, D. Liu, A. K. Honma, W. G. Scott, I. Nakamura, S. D. Bird, D. Axen, A. Jawahery, Peter Sherwood, Alexander Wagner, J. Ludwig, D. Glenzinski, Shoji Asai, Dezso Horvath, M. J. Losty, Jean-Arcady Meyer, Giora Mikenberg, S. F. Ashby, K. Runge, P. Bock, I. J. Bloodworth, A. D. Schaile, Gabriella Pasztor, P. Vannerem, Georges Azuelos, E. Tsur, S. A. Robins, G. A. Snow, C. P. Ward, S. Söldner-Rembold, M. Verzocchi, Yoram Rozen, K. W. Bell, R. Liebisch, K. Ackerstaff, J. Pálinkás, J. C. Hill, J. Polok, D. Karlen, Daniel Lellouch, Erez Etzion, Takehiko Mori, Stefan Kluth, P. Mättig, Shlomit Tarem, B. Surrow, J. Goldberg, B. Nellen, I. Cohen, Christoph Rembser, Matthias Schröder, M. Thiergen, K. Graham, Tara Shears, A. J. Martin, W. Mader, C. K. Hargrove, A. Biguzzi, J. G. Layter, S. Betts, M. Hapke, P. E.L. Clarke, J. P. Martin, M. J. Oreglia, S. De Jong, H. Rick, G. G. Hanson, J. R. Carter, G. Giacomelli, I. Lawson, James Pinfold, R. Perez-Ochoa, R. Seuster, J. Gascon, G. N. Patrick, A. De Roeck, M. Kobel, V. Zacek, J. W. Gary, M. S. Dixit, Frans Meijers, D. S. Koetke, Marcello Mannelli, K. Stoll, Andris Skuja, S. Petzold, Randall Sobie, G. D. Lafferty, Tetsuro Mashimo, M. F. Turner-Watson, Guenter Duckeck, Richard Teuscher, A. S. Turcot, F. Fiedler, W. Gorn, M. Kolrep, S. B. Anderson, P. Scharff-Hansen, Stan Bentvelsen, and A. M. Smith
Subjects: Physics, Physics and Astronomy (miscellaneous), Branching fraction, High Energy Physics::Phenomenology, High Energy Physics::Experiment, B meson, Atomic physics, Lambda, Engineering (miscellaneous)
Abstract: The product branching ratio, $f ({\rm b} \to \Lambda_{\rm b}) \cdot{\rm BR} (\Lambda_{\rm b} \to \Lambda{\rm X})$, where $\Lambda_{\rm b}$ denotes any weakly-decaying b–baryon, has been measured using the OPAL detector at LEP. $\Lambda_{\rm b}$'s are selected by the presence of energetic $\Lambda$ particles in bottom events tagged by the presence of displaced secondary vertices. A fit to the momenta of the $\Lambda$ particles separates signal from B meson and fragmentation backgrounds. The measured product branching ratio is  Combined with a previous OPAL measurement, one obtains 
Published: 1999

34. Search for scalar top and scalar bottom quarks at = 189 GeV at LEP

Author: G Abbiendi, K Ackerstaff, G Alexander, J Allison, N Altekamp, K.J Anderson, S Anderson, S Arcelli, S Asai, S.F Ashby, D Axen, G Azuelos, A.H Ball, E Barberio, R.J Barlow, J.R Batley, S Baumann, J Bechtluft, T Behnke, K.W Bell, G Bella, A Bellerive, S Bentvelsen, S Bethke, S Betts, O Biebel, A Biguzzi, V Blobel, I.J Bloodworth, P Bock, J Böhme, D Bonacorsi, M Boutemeur, S Braibant, P Bright-Thomas, L Brigliadori, R.M Brown, H.J Burckhart, P Capiluppi, R.K Carnegie, A.A Carter, J.R Carter, C.Y Chang, D.G Charlton, D Chrisman, C Ciocca, P.E.L Clarke, E Clay, I Cohen, J.E Conboy, O.C Cooke, C Couyoumtzelis, R.L Coxe, M Cuffiani, S Dado, G.M Dallavalle, R Davis, S De Jong, A de Roeck, P Dervan, K Desch, B Dienes, M.S Dixit, J Dubbert, E Duchovni, G Duckeck, I.P Duerdoth, P.G Estabrooks, E Etzion, F Fabbri, A Fanfani, M Fanti, A.A Faust, F Fiedler, M Fierro, I Fleck, R Folman, A Frey, A Fürtjes, D.I Futyan, P Gagnon, J.W Gary, J Gascon, S.M Gascon-Shotkin, G Gaycken, C Geich-Gimbel, G Giacomelli, P Giacomelli, V Gibson, W.R Gibson, D.M Gingrich, D Glenzinski, J Goldberg, W Gorn, C Grandi, K Graham, E Gross, J Grunhaus, M Gruwé, G.G Hanson, M Hansroul, M Hapke, K Harder, A Harel, C.K Hargrove, M Hauschild, C.M Hawkes, R Hawkings, R.J Hemingway, M Herndon, G Herten, R.D Heuer, M.D Hildreth, J.C Hill, P.R Hobson, M Hoch, A Hocker, K Hoffman, R.J Homer, A.K Honma, D Horváth, K.R Hossain, R Howard, P Hüntemeyer, P Igo-Kemenes, D.C Imrie, K Ishii, F.R Jacob, A Jawahery, H Jeremie, M Jimack, C.R Jones, P Jovanovic, T.R Junk, J Kanzaki, D Karlen, V Kartvelishvili, K Kawagoe, T Kawamoto, P.I Kayal, R.K Keeler, R.G Kellogg, B.W Kennedy, D.H Kim, A Klier, T Kobayashi, M Kobel, T.P Kokott, M Kolrep, S Komamiya, R.V Kowalewski, T Kress, P Krieger, J von Krogh, T Kuhl, P Kyberd, G.D Lafferty, H Landsman, D Lanske, J Lauber, S.R Lautenschlager, I Lawson, J.G Layter, A.M Lee, D Lellouch, J Letts, L Levinson, R Liebisch, B List, C Littlewood, A.W Lloyd, S.L Lloyd, F.K Loebinger, G.D Long, M.J Losty, J Lu, J Ludwig, D Liu, A Macchiolo, A Macpherson, W Mader, M Mannelli, S Marcellini, C Markopoulos, A.J Martin, J.P Martin, G Martinez, T Mashimo, P Mättig, W.J McDonald, J McKenna, E.A Mckigney, T.J McMahon, R.A McPherson, F Meijers, S Menke, F.S Merritt, H Mes, J Meyer, A Michelini, S Mihara, G Mikenberg, D.J Miller, R Mir, W Mohr, A Montanari, T Mori, K Nagai, I Nakamura, H.A Neal, R Nisius, S.W O'Neale, F.G Oakham, F Odorici, H.O Ogren, M.J Oreglia, S Orito, J Pálinkás, G Pásztor, J.R Pater, G.N Patrick, J Patt, R Perez-Ochoa, S Petzold, P Pfeifenschneider, J.E Pilcher, J Pinfold, D.E Plane, P Poffenberger, B Poli, J Polok, M Przybycień, C Rembser, H Rick, S Robertson, S.A Robins, N Rodning, J.M Roney, S Rosati, K Roscoe, A.M Rossi, Y Rozen, K Runge, O Runolfsson, D.R Rust, K Sachs, T Saeki, O Sahr, W.M Sang, E.K.G Sarkisyan, C Sbarra, A.D Schaile, O Schaile, P Scharff-Hansen, J Schieck, S Schmitt, A Schöning, M Schröder, M Schumacher, C Schwick, W.G Scott, R Seuster, T.G Shears, B.C Shen, C.H Shepherd-Themistocleous, P Sherwood, G.P Siroli, A Sittler, A Skuja, A.M Smith, G.A Snow, R Sobie, S Söldner-Rembold, S Spagnolo, M Sproston, A Stahl, K Stephens, J Steuerer, K Stoll, D Strom, R Ströhmer, B Surrow, S.D Talbot, P Taras, S Tarem, R Teuscher, M Thiergen, J Thomas, M.A Thomson, E Torrence, S Towers, I Trigger, Z Trócsányi, E Tsur, A.S Turcot, M.F Turner-Watson, I Ueda, R Van Kooten, P Vannerem, M Verzocchi, H Voss, F Wäckerle, A Wagner, C.P Ward, D.R Ward, P.M Watkins, A.T Watson, N.K Watson, P.S Wells, N Wermes, J.S White, G.W Wilson, J.A Wilson, T.R Wyatt, S Yamashita, G Yekutieli, V Zacek, and D Zer-Zion
Subjects: Quark, Nuclear and High Energy Physics, Top quark, Particle physics, High Energy Physics::Lattice, Nuclear Theory, FOS: Physical sciences, Fizikai tudományok, 7. Clean energy, 01 natural sciences, Bottom quark, High Energy Physics - Experiment, Charm quark, High Energy Physics - Experiment (hep-ex), Természettudományok, 0103 physical sciences, 010306 general physics, Physics, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Scalar (physics), Neutralino, High Energy Physics::Experiment, Neutrino, Particle Physics - Experiment, Lepton
Abstract: Searches for a scalar top quark and a scalar bottom quark have been performed using a data sample of 182 pb-1 at a centre-of-mass energy of 189 GeV collected with the OPAL detector at LEP. No evidence for a signal was found. The 95% confidence level lower limit on the scalar top quark mass is 90.3 GeV if the mixing angle between the supersymmetric partners of the left- and right-handed states of the top quark is zero. In the worst case, when the scalar top quark decouples from the Z boson, the lower limit is 87.2 GeV. These limits were obtained assuming that the scalar top quark decays into a charm quark and the lightest neutralino, and that the mass difference between the scalar top quark and the lightest neutralino is larger than 10 GeV. The complementary decay mode of the scalar top quark decaying into a bottom quark, a charged lepton and a scalar neutrino has also been studied. From a search for the scalar bottom quark, a mass limit of 88.6 GeV was obtained if the mass difference between the scalar bottom quark and the lightest neutralino is larger than 7 GeV. These limits significantly improve the previous OPAL limits., 18 pages, LaTeX, including 4 eps figures, submitted to Physics Letters B
Published: 1999

35. Colour reconnection studies in e+e−→W+W− at GeV

Author: G. Abbiendi, K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, R. Davis, S. De Jong, A. de Roeck, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, F. Fabbri, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, I. Fleck, R. Folman, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, C.K. Hargrove, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, P.R. Hobson, M. Hoch, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Liu, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, C. Markopoulos, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, J. Polok, M. Przybycień, C. Rembser, H. Rick, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, J. Steuerer, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, I. Ueda, R. Van Kooten, P. Vannerem, M. Verzocchi, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Quantum chromodynamics, Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, Hadron, Observable, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Charged particle, 0103 physical sciences, Statistical precision, High Energy Physics::Experiment, Rapidity, Multiplicity (chemistry), 010306 general physics, Boson
Abstract: The predicted effects of final state interactions such as colour reconnection are investigated by measuring properties of hadronic decays of W bosons, recorded at a centre-of-mass energy of sqrt(s)=182.7 GeV in the OPAL detector at LEP. Dependence on the modelling of hadronic W decays is avoided by comparing W+W- -> qqqq events with the non-leptonic component of W+W- -> qqlnu events. The scaled momentum distribution, its mean value, x_p, and that of the charged particle multiplicity, n_ch, are measured and found to be consistent in the two channels. The measured differences are: Diff(x_p) = +0.7 +- 0.8 +- 0.6 and Diff(n_ch) = (-0.09 +- 0.09 +-0.05)*10**-2. In addition, measurements of rapidity and thrust are performed for W+W- -> qqqq events. The data are described well by standard QCD models and disfavour one model of colour reconnection within the ARIADNE program. The current implementation of the ELLIS-GEIGER model of colour reconnection is excluded. At the current level of statistical precision no evidence for colour reconnection effects was found in the observables studied. The predicted effect of colour reconnection on OPAL measurements of M_W is also quantified in the context of models studied.
Published: 1999

36. Search for anomalous photonic events with missing energy in ${\rm e}^+{\rm e}^-$ collisions at $\sqrt{s}$ = 130, 136 and 183 GeV

Author: Sachio Komamiya, A. T. Watson, M. Boutemeur, F. S. Merritt, F. Scharf, T. P. Kokott, J. Letts, T. Saeki, Satoshi Mihara, German Martinez, J. Bechtluft, J. A. McKenna, G. G. Hanson, P. Scharff-Hansen, R. Davis, Randall Sobie, G. D. Lafferty, K. Sachs, S. Betts, M. Hapke, M. Fanti, G. Giacomelli, M. J. Oreglia, I. Lawson, Shlomo Dado, J. R. Carter, G. N. Patrick, A. M. Smith, Dave Charlton, R. Bartoldus, A. De Roeck, W. R. Gibson, H. O. Ogren, Christoph Geich-Gimbel, N. Altekamp, H. Voss, Guenter Duckeck, J. M. Roney, Robert McPherson, J. Grunhaus, S. R. Lautenschlager, K. Stoll, Andris Skuja, D. M. Strom, Gregor Herten, K. Harder, R. J. Barlow, G. Gaycken, P. G. Bright-Thomas, R. D. Heuer, D. J. Miller, Fabrizio Fabbri, D. C. Imrie, Claire Shepherd-Themistocleous, M. Schumacher, S. Petzold, R. Bürgin, O. Runolfsson, R. M. Brown, Lorne Levinson, M. S. Dixit, Frans Meijers, Giora Mikenberg, S. F. Ashby, Koichi Nagai, J. Schieck, Tetsuro Mashimo, Achim Stahl, Vakhtang Kartvelishvili, Paul Kyberd, J. E. Conboy, A. Fürtjes, C. Y. Chang, Ehud Duchovni, W. Mohr, M. Jimack, G. P. Siroli, J. E. Pilcher, F. Odorici, R. Van Kooten, T. R. Junk, A. Biguzzi, A. A. Faust, W. Gorn, P. Taras, F. K. Loebinger, P. S. Wells, Claudio Grandi, J. S. White, Christoph Schwick, A. Michelini, J. Steuerer, J. G. Layter, A. W. Lloyd, Ekg Sarkisyan, R. J. Hemingway, C. Hartmann, S. B. Anderson, D. E. Plane, Terry Richard Wyatt, Gideon Bella, K. Stephens, Stephen Hillier, H. A. Neal, G. M. Dallavalle, Ivor Fleck, G. W. Wilson, Satoshi Tanaka, Joleen Pater, A. D. Schaile, Gabriella Pasztor, M. Hauschild, C. Markopoulos, P. Vannerem, M. A. Thomson, A. Macpherson, H. J. Burckhart, Jacqueline Batley, F. Wäckerle, C. Littlewood, B. W. Kennedy, James Pinfold, R. Perez-Ochoa, R. Seuster, P. Jovanovic, A. Klier, Austin Ball, D. M. Gingrich, T. Kobayashi, E. K. U. Gross, L. Brigliadori, V. Gibson, H. Mes, S. M. Gascon-Shotkin, Peter Krieger, J. Gascon, R. Howard, Stan Bentvelsen, M. Sproston, K. Roscoe, G. A. Snow, C. P. Ward, Alessandro Montanari, D. Lanske, M. F. Turner-Watson, I. Trigger, I. P. Duerdoth, S. Braibant, A. Macchiolo, Peter R Hobson, D. R. Rust, P. E.L. Clarke, Klaus Kurt Desch, E. Torrence, M. Kobel, S. Söldner-Rembold, D. R. Ward, T. Kress, C. M. Hawkes, R. Mir, J. P. Martin, E. Clay, Otmar Biebel, R. Kowalewski, V. Zacek, R. Hawkings, S. W. O'Neale, K. J. Anderson, D. Zer-Zion, O. C. Cooke, P. Hüntemeyer, S. Arcelli, A. M. Lee, P. I. Kayal, Georges Azuelos, P. Pfeifenschneider, T. Kuhl, John Allison, J. W. Gary, Raimund Ströhmer, Norbert Wermes, E. von Törne, Sherry Towers, T. Kawamoto, S. De Jong, E. Tsur, D. S. Koetke, Marcello Mannelli, Richard Teuscher, A. S. Turcot, C. R. Jones, S. Orito, J. Patt, Richard Nisius, A. M. Rossi, André Schöning, P. Poffenberger, M. Fierro, M. Verzocchi, K. W. Bell, H. Rick, O. Sahr, F. G. Oakham, B. List, Marco Cuffiani, F. Fiedler, J. Pálinkás, Kiyotomo Kawagoe, B. Schmitt, E. L. Barberio, Gideon Alexander, Paolo Giacomelli, M. Hansroul, Paolo Capiluppi, J. C. Hill, Beatrix Dienes, C. Burgard, R. J. Homer, R. G. Kellogg, R. L. Coxe, W. J. McDonald, B. C. Shen, A. Hocker, M. Kolrep, Siegfried Bethke, D. Liu, A. K. Honma, D. Chrisman, G. D. Long, K. R. Hossain, Stefano Marcellini, Volker Blobel, W. G. Scott, I. Nakamura, Stephen Lloyd, W. M. Sang, Claudia Ciocca, D. Glenzinski, Dezso Horvath, M. J. Losty, Jean-Arcady Meyer, Michael Hildreth, Alain Bellerive, N. L. Rodning, C. Sbarra, F. R. Jacob, Daniele Bonacorsi, J. Lauber, J. von Krogh, S. D. Talbot, M. Gruwé, L. A. del Pozo, T. J. McMahon, C. Couyoumtzelis, J. Dubbert, R. K. Carnegie, M. Herndon, D. Eatough, T. Behnke, M. Bobinski, J. A. Wilson, J. Böhme, D. Lazic, P. Gagnon, G. Yekutieli, M. Przybycień, A. A. Carter, Ron Folman, A. Sittler, Zoltan Laszlo Trocsanyi, Giovanni Abbiendi, S. D. Bird, D. Axen, A. Jawahery, Peter Sherwood, Stefan Schmitt, Alexander Wagner, J. Ludwig, K. Runge, P. Bock, Shoji Asai, P. G. Estabrooks, R. K. Keeler, Daniel Lellouch, N. K. Watson, Takehiko Mori, P. Mättig, P. M. Watkins, I. J. Bloodworth, S. Baumann, Yoram Rozen, E. A. Mckigney, J. Polok, D. Karlen, D. I. Futyan, J. Goldberg, B. Nellen, H. G. Evans, I. Cohen, Christoph Rembser, Erez Etzion, Stefan Kluth, Shlomit Tarem, B. Surrow, S. A. Robins, R. Liebisch, K. Ackerstaff, A. J. Martin, S. Yamashita, P. Igo-Kemenes, K. Ishii, H. Jeremie, W. Mader, O. Schaile, C. K. Hargrove, S. Robertson, Matthias Schröder, Sven Menke, M. Thiergen, and Tara Shears
Subjects: Physics, Particle physics, Missing energy, Physics and Astronomy (miscellaneous), Physics beyond the Standard Model, Standard Model, Nuclear physics, Pair production, Neutralino, High Energy Physics::Experiment, Gravitino, Production (computer science), Engineering (miscellaneous), Energy (signal processing)
Abstract: Photonic events with large missing energy have been observed in $\mathrm e^+e^-$ collisions at centre-of-mass energies of 130, 136 and 183 GeV collected in 1997 using the OPAL detector at LEP. Results are presented for event topologies with a single photon and missing transverse energy or with an acoplanar photon pair. Cross-section measurements are performed within the kinematic acceptance of each selection. These results are compared with the expectations from the Standard Model process ${\rm e}^+{\rm e}^-\to\nu\overline{\nu}$ + photon(s). No evidence is observed for new physics contributions to these final states. Using the data at $\sqrt{s}$ = 183 GeV, upper limits on ${\sigma({\rm e^+e^-}\to{\rm XY})\cdot{\rm BR}(\rm X \to Y \gamma)}$ and ${\sigma({\rm e^+e^-}\to{\rm XX})\cdot{\rm BR}^2(\rm X \to Y \gamma)}$ are derived for the case of stable and invisible Y. These limits apply to single and pair production of excited neutrinos ( $\rm X = \nu^*, Y = \nu$ ), to neutralino production ( $\rm X={{\tilde{\chi}}^{0}}_{2}, Y={{\tilde{\chi}}^{0}}_{1}$ ) and to supersymmetric models in which $\rm X = {{\tilde{\chi}}^{0}}_{1}$ and $\rm Y=\tilde{\mathrm{G}}$ is a light gravitino.
Published: 1999

37. Measurements of flavour-dependent fragmentation functions in ${\bf Z^{0} \rightarrow{\rm q}\bar{\rm q}}$ events

Author: J. von Krogh, R. Bartoldus, G. Yekutieli, M. Przybycień, A. A. Carter, Ron Folman, J. Letts, M. Gruwé, L. A. del Pozo, P. G. Bright-Thomas, K. Stephens, M. Fanti, T. J. McMahon, C. Couyoumtzelis, J. Dubbert, R. K. Carnegie, M. Herndon, Daniel Lellouch, M. Bobinski, C. Y. Chang, J. A. Wilson, J. Böhme, H. O. Ogren, K. Roscoe, M. Schumacher, E. Lefebvre, D. Lazic, Takehiko Mori, P. Mättig, F. Odorici, Randall Sobie, T. Schorner, S. D. Bird, John Allison, Reda Tafirout, Klaus Kurt Desch, G. D. Lafferty, Christoph Geich-Gimbel, S. M. Gascon-Shotkin, Achim Stahl, James Pinfold, R. Perez-Ochoa, R. Seuster, C. Littlewood, V. Gibson, E. Torrence, F. Scharf, K. Sachs, Shlomo Dado, Georges Azuelos, E. Tsur, German Martinez, J. Gascon, T. R. Junk, D. Axen, P. E.L. Clarke, A. Jawahery, Robert McPherson, M. Verzocchi, H. A. Neal, I. Trigger, E. Clay, K. W. Bell, R. G. Kellogg, J. Pálinkás, D. R. Ward, T. Kress, J. C. Hill, J. P. Martin, Dave Charlton, P. G. Estabrooks, Vakhtang Kartvelishvili, Mathieu Doucet, V. Zacek, T. Behnke, W. J. McDonald, Peter Sherwood, R. K. Keeler, B. C. Shen, Stefano Marcellini, M. F. Turner-Watson, J. W. Gary, R. D. Heuer, D. S. Koetke, W. R. Gibson, Stefan Schmitt, Siegfried Bethke, J. E. Conboy, R. Kowalewski, S. De Jong, Marcello Mannelli, Fabrizio Fabbri, M. A. Thomson, A. K. Honma, W. G. Scott, Guenter Duckeck, A. Fürtjes, N. K. Watson, W. M. Sang, Kiyotomo Kawagoe, Peter R Hobson, R. Bürgin, Alexander Wagner, I. Nakamura, E. K. U. Gross, H. Mes, P. Scharff-Hansen, A. M. Rossi, K. Nagai, I. P. Duerdoth, S. Braibant, J. Ludwig, D. Zer-Zion, K. Runge, P. Bock, P. M. Watkins, M. Sproston, A. Macchiolo, O. C. Cooke, Gregor Herten, P. Pfeifenschneider, H. Rick, Shoji Asai, Giora Mikenberg, A. Joly, R. M. Brown, Lorne Levinson, A. M. Smith, S. F. Ashby, K. R. Hossain, D. R. Rust, C. M. Hawkes, D. Glenzinski, J. Patt, André Schöning, K. Stoll, Andris Skuja, M. Boutemeur, F. S. Merritt, I. J. Bloodworth, P. Hüntemeyer, S. B. Anderson, P. Gagnon, S. Petzold, C. Sbarra, Satoshi Mihara, Gideon Alexander, Dezso Horvath, M. J. Losty, F. R. Jacob, Jean-Arcady Meyer, Tetsuro Mashimo, O. Sahr, Paolo Capiluppi, J. Grunhaus, C. Hartmann, D. E. Plane, A. M. Lee, Gideon Bella, A. D. Schaile, W. Gorn, Paul Kyberd, F. K. Loebinger, A. Sittler, Stephen Hillier, E. von Törne, Gabriella Pasztor, J. M. Roney, R. L. Coxe, Zoltan Laszlo Trocsanyi, Richard Nisius, Stan Bentvelsen, M. Fierro, G. M. Dallavalle, Yoram Rozen, H. J. Burckhart, Jacqueline Batley, P. Vannerem, Michael Hildreth, J. Steuerer, Ivor Fleck, Silvia Arcelli, J. Bechtluft, B. List, J. A. McKenna, D. Lui, A. Hocker, Paolo Giacomelli, Joleen Pater, Marco Cuffiani, Richard Teuscher, G. A. Snow, A. Klier, A. S. Turcot, F. Fiedler, D. Chrisman, G. D. Long, M. Hansroul, Ekg Sarkisyan, C. P. Ward, Sachio Komamiya, N. L. Rodning, R. Van Kooten, Theodoros Geralis, J. Lauber, J. Schieck, Volker Blobel, A. T. Watson, W. Mohr, G. G. Hanson, C. Burgard, S. Söldner-Rembold, B. Poli, R. J. Homer, T. P. Kokott, Stephen Lloyd, T. Saeki, G. Giacomelli, I. Lawson, F. Wäckerle, S. D. Talbot, J. E. Pilcher, D. M. Gingrich, Alessandra Fanfani, R. Davis, Claire Shepherd-Themistocleous, Ehud Duchovni, S. Baumann, J. Polok, A. De Roeck, M. Kobel, D. Karlen, M. Kolrep, D. Eatough, M. Jimack, C. R. Jones, G. W. Wilson, A. Michelini, H. M. Fischer, E. A. Mckigney, M. S. Dixit, D. C. Imrie, P. Vikas, A. A. Faust, Frans Meijers, Satoshi Tanaka, T. Kobayashi, D. Lanske, S. Betts, M. Hapke, G. P. Siroli, S. R. Lautenschlager, A. Biguzzi, J. G. Layter, Christoph Schwick, Claudia Ciocca, O. Runolfsson, D. I. Futyan, Claudio Grandi, M. J. Oreglia, A. W. Lloyd, S. Yamashita, P. Igo-Kemenes, S. A. Robins, K. Ishii, H. Jeremie, M. Hauschild, C. Markopoulos, R. Liebisch, K. Ackerstaff, J. R. Carter, G. N. Patrick, O. Schaile, Otmar Biebel, S. Robertson, P. Taras, Raimund Ströhmer, P. Poffenberger, Beatrix Dienes, Sven Menke, S. W. O'Neale, K. J. Anderson, P. I. Kayal, Erez Etzion, Stefan Kluth, Shlomit Tarem, Norbert Wermes, Sherry Towers, T. Kawamoto, S. Orito, J. Goldberg, B. Nellen, H. G. Evans, I. Cohen, Christoph Rembser, P. S. Wells, Terry Richard Wyatt, A. Macpherson, A. J. Martin, C. K. Hargrove, Tara Shears, R. Howard, R. Mir, R. Hawkings, J. S. White, Matthias Schröder, M. Thiergen, D. M. Strom, F. G. Oakham, B. Schmitt, E. L. Barberio, N. Altekamp, H. Voss, R. J. Barlow, D. J. Miller, R. J. Hemingway, B. W. Kennedy, P. Jovanovic, Austin Ball, Peter Krieger, and Alessandro Montanari
Subjects: Quark, Physics, Particle physics, Physics and Astronomy (miscellaneous), Meson, 010308 nuclear & particles physics, High Energy Physics::Lattice, Electron–positron annihilation, High Energy Physics::Phenomenology, Flavour, 01 natural sciences, Bottom quark, Charged particle, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Charm (quantum number), 010306 general physics, Maxima, Engineering (miscellaneous)
Abstract: Fragmentation functions for charged particles in ${\rm Z}^0 \rightarrow {\rm q}\bar{\rm q}$ events have been measured for bottom (b), charm (c) and light (uds) quarks as well as for all flavours together. The results are based on data recorded between 1990 and 1995 using the OPAL detector at LEP. Event samples with different flavour compositions were formed using reconstructed ${\rm D}^{*\pm}$ mesons and secondary vertices. The $\xi_{\rm p} =\ln(1/x_{\rm p})$ distributions and the position of their maxima $\xi_0$ are also presented separately for uds, c and b quark events. The fragmentation function for b quarks is significantly softer than for uds quarks.
Published: 1999

38. Search for baryon and lepton number violating Z0 decays

Author: G. Abbiendi, K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, A. Bellerive, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, P. Bock, J. Böhme, D. Bonacorsi, M. Boutemeur, S. Braibant, P. Bright-Thomas, L. Brigliadori, R.M. Brown, H.J. Burckhart, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, R. Davis, S. De Jong, A. de Roeck, P. Dervan, K. Desch, B. Dienes, M.S. Dixit, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, F. Fabbri, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, I. Fleck, R. Folman, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, G. Gaycken, C. Geich-Gimbel, G. Giacomelli, P. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, K. Graham, E. Gross, J. Grunhaus, M. Gruwé, G.G. Hanson, M. Hansroul, M. Hapke, K. Harder, A. Harel, C.K. Hargrove, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, P.R. Hobson, M. Hoch, A. Hocker, K. Hoffman, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, C.R. Jones, P. Jovanovic, T.R. Junk, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, D.H. Kim, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, T. Kuhl, P. Kyberd, G.D. Lafferty, H. Landsman, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Liu, A. Macchiolo, A. Macpherson, W. Mader, M. Mannelli, S. Marcellini, C. Markopoulos, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, J. Polok, M. Przybycień, C. Rembser, H. Rick, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, S. Spagnolo, M. Sproston, A. Stahl, K. Stephens, J. Steuerer, K. Stoll, D. Strom, R. Ströhmer, B. Surrow, S.D. Talbot, S. Tanaka, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, J. Thomas, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, I. Ueda, R. Van Kooten, P. Vannerem, M. Verzocchi, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Detector, FOS: Physical sciences, Fizikai tudományok, Charge (physics), 01 natural sciences, Lepton number, High Energy Physics - Experiment, Baryon, High Energy Physics - Experiment (hep-ex), Természettudományok, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Particle Physics - Experiment, Conjugate
Abstract: Using data collected with the OPAL detector at LEP, we have searched for the processes e+e- -> Z0 -> p e-, p mu- and the charge conjugate final-states. These would violate the conservation of the baryon-number B, lepton-number L and the fermion-number n = (B+L). No evidence for such decays has been found, and the 95% confidence level upper limits on the partial widths Z0 -> p e and Z0 -> p mu are found to be 4.6 and 4.4 keV respectively., 16 pages, LaTeX, 2 ps figs included, submitted to Physics Letters B
Published: 1999

39. A measurement of the τ→ν branching ratio

Author: S. M. Gascon-Shotkin, P. Poffenberger, A. D. Schaile, Gabriella Pasztor, John Allison, G. Gaycken, P. G. Bright-Thomas, J. Lauber, Erez Etzion, G. Yekutieli, A. J. Martin, M. Przybycień, Stefan Kluth, Shlomit Tarem, Beatrix Dienes, M. Schumacher, P. Gagnon, P. Vannerem, S. D. Talbot, A. Sittler, Zoltan Laszlo Trocsanyi, Dong Hee Kim, T. Kress, Daniel Lellouch, R. G. Kellogg, A. M. Rossi, A. A. Carter, Ron Folman, D. Eatough, Takehiko Mori, F. Odorici, B. Surrow, G. A. Snow, C. P. Ward, T. Behnke, W. Mader, Stefano Marcellini, S. D. Bird, P. Mättig, C. K. Hargrove, S. Söldner-Rembold, H. A. Neal, D. Axen, A. Jawahery, M. Fanti, C. Y. Chang, S. A. Robins, P. G. Estabrooks, R. K. Keeler, D. C. Imrie, Dave Charlton, Claire Shepherd-Themistocleous, Peter Sherwood, Alexander Wagner, Giovanni Abbiendi, J. Ludwig, K. Runge, P. Bock, N. K. Watson, Matthias Schröder, P. Taras, Paul Kyberd, F. K. Loebinger, K. Hoffman, R. Liebisch, K. Ackerstaff, J. Steuerer, T. R. Junk, G. P. Siroli, E. Tsur, Ivor Fleck, M. Thiergen, S. R. Lautenschlager, Stefan Schmitt, P. S. Wells, P. M. Watkins, T. J. McMahon, M. Verzocchi, K. W. Bell, Joleen Pater, C. Couyoumtzelis, A. Klier, Christoph Schwick, R. J. Hemingway, J. Pálinkás, S. B. Anderson, M. Boutemeur, F. S. Merritt, A. A. Faust, R. D. Heuer, J. Dubbert, R. K. Carnegie, K. Sachs, M. Herndon, James Pinfold, R. Perez-Ochoa, R. Seuster, Terry Richard Wyatt, J. C. Hill, Robert McPherson, Christopher Hawkes, J. A. Wilson, J. Böhme, Shoji Asai, W. M. Sang, Shlomo Dado, L. Brigliadori, O. Runolfsson, Claudia Ciocca, B. W. Kennedy, P. Jovanovic, Gideon Bella, I. J. Bloodworth, Gregor Herten, W. J. McDonald, B. C. Shen, J. Gascon, S. Baumann, D. Lazic, K. Graham, H. J. Burckhart, Jacqueline Batley, A. Macpherson, Tara Shears, Daniele Bonacorsi, Fabrizio Fabbri, Giora Mikenberg, J. Goldberg, Siegfried Bethke, D. Liu, A. K. Honma, E. A. Mckigney, Austin Ball, Yoram Rozen, J. Bechtluft, J. A. McKenna, Peter Krieger, V. Zacek, Claudio Grandi, W. G. Scott, Michael Hildreth, B. Nellen, Stan Bentvelsen, C. Sbarra, G. Azuelos, F. R. Jacob, S. F. Ashby, I. Nakamura, J. S. White, Ekg Sarkisyan, R. Van Kooten, Kiyotomo Kawagoe, J. E. Pilcher, J. W. Gary, N. L. Rodning, D. S. Koetke, A. Macchiolo, J. von Krogh, S. W. O'Neale, J. Letts, Marcello Mannelli, R. Bartoldus, P. Dervan, J. Polok, D. Karlen, Alessandro Montanari, D. Glenzinski, H. Mes, I. P. Duerdoth, A. W. Lloyd, H. O. Ogren, K. J. Anderson, C. R. Jones, K. Stoll, Andris Skuja, S. Petzold, Dezso Horvath, M. J. Losty, M. Gruwé, D. I. Futyan, Christoph Geich-Gimbel, R. Howard, Jean-Arcady Meyer, G. W. Wilson, Tetsuro Mashimo, T. Kuhl, Richard Nisius, M. F. Turner-Watson, M. Hauschild, C. Markopoulos, F. Wäckerle, S. Braibant, A. Bellerive, B. List, Vakhtang Kartvelishvili, R. Mir, D. M. Gingrich, Randall Sobie, G. D. Lafferty, Marco Cuffiani, J. E. Conboy, A. Fürtjes, K. R. Hossain, W. Gorn, I. Cohen, R. Hawkings, Christoph Rembser, D. Lanske, A. Harel, P. Hüntemeyer, Ikuo Ueda, D. M. Strom, P. Scharff-Hansen, H. Landsman, D. R. Rust, A. M. Smith, Guenter Duckeck, M. Fierro, A. M. Lee, Richard Teuscher, A. S. Turcot, E. von Törne, F. Fiedler, M. Kolrep, F. G. Oakham, B. Schmitt, E. L. Barberio, N. Altekamp, H. Voss, R. J. Barlow, D. J. Miller, S. Spagnolo, S. Yamashita, P. Igo-Kemenes, M. Hoch, K. Ishii, H. Jeremie, O. Schaile, S. Robertson, Sven Menke, Ehud Duchovni, M. Jimack, A. Michelini, Satoshi Tanaka, T. Kobayashi, Peter R Hobson, J. M. Roney, R. L. Coxe, D. Zer-Zion, Sachio Komamiya, A. T. Watson, A. Hocker, Koichi Nagai, J. Schieck, D. Chrisman, G. D. Long, T. P. Kokott, W. Mohr, Volker Blobel, Achim Stahl, T. Saeki, R. Davis, Stephen Lloyd, J. Grunhaus, R. Kowalewski, S. Arcelli, F. Scharf, German Martinez, Juergen Thomas, A. Biguzzi, J. G. Layter, Gideon Alexander, M. A. Thomson, Paolo Capiluppi, P. E.L. Clarke, J. P. Martin, E. K. U. Gross, S. De Jong, H. Rick, M. Sproston, G. G. Hanson, G. Giacomelli, I. Lawson, K. Stephens, A. De Roeck, M. Kobel, C. Littlewood, M. S. Dixit, Frans Meijers, O. C. Cooke, P. Pfeifenschneider, V. Gibson, I. Trigger, D. R. Ward, J. Patt, André Schöning, O. Sahr, Satoshi Mihara, Otmar Biebel, Paolo Giacomelli, M. Hansroul, R. J. Homer, P. I. Kayal, Norbert Wermes, Sherry Towers, T. Kawamoto, W. R. Gibson, S. Orito, K. Harder, S. Betts, M. Hapke, M. J. Oreglia, J. R. Carter, G. N. Patrick, R. M. Brown, Lorne Levinson, C. Hartmann, D. E. Plane, G. M. Dallavalle, K. Roscoe, Klaus Kurt Desch, E. Torrence, E. Clay, and Raimund Ströhmer
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Electron energy spectrum, 010308 nuclear & particles physics, Branching fraction, Electron–positron annihilation, 0103 physical sciences, Strong coupling, Analytical chemistry, Mass scale, 010306 general physics, 01 natural sciences
Abstract: The branching ratio for the decay τ − → e − ν e ν τ has been measured using Z 0 decay data collected by the OPAL experiment at LEP. In total 33 073 τ − → e − ν e ν τ candidates were identified from a sample of 186 197 selected τ decays, giving a branching ratio of B (τ − → e − ν e ν τ )=(17.81±0.09 (stat) ±0.06 (syst) )% . This result is combined with other measurements to test e - μ and μ - τ universality in charged-current weak interactions. Additionally, the strong coupling constant α s ( m τ 2 ) has been extracted from B (τ − → e − ν e ν τ ) and evolved to the Z 0 mass scale, giving α s ( m Z 2 )=0.1204±0.0011 (exp)±0.0019 (theory).
Published: 1999

40. Search for scalar top and scalar bottom quarks at $\sqrt{s}$ = 183 GeV at LEP

Author: S. Petzold, W. J. McDonald, B. C. Shen, Tetsuro Mashimo, Matthias Schröder, K. Nagai, K. Stephens, R. Bartoldus, Siegfried Bethke, A. K. Honma, W. G. Scott, M. Thiergen, I. Nakamura, H. O. Ogren, W. Gorn, Christoph Geich-Gimbel, D. R. Rust, D. Glenzinski, Dezso Horvath, M. J. Losty, Jean-Arcady Meyer, V. Gibson, A. M. Lee, E. von Törne, S. Yamashita, P. Igo-Kemenes, K. Ishii, H. Jeremie, Vakhtang Kartvelishvili, T. R. Junk, J. E. Conboy, A. Fürtjes, I. Trigger, D. R. Ward, T. Kress, R. W. Springer, R. Van Kooten, M. Boutemeur, F. S. Merritt, S. Braibant, Georges Azuelos, E. Tsur, A. D. Schaile, Gabriella Pasztor, J. Bechtluft, J. A. McKenna, O. Schaile, M. Verzocchi, K. W. Bell, S. B. Anderson, P. Szymanski, J. Pálinkás, M. Schumacher, F. Wäckerle, E. Lefebvre, G. Yekutieli, E. do Couto e Silva, S. Robertson, Gregor Herten, J. C. Hill, U. Jost, R. Mir, R. Hawkings, B. Wilkens, D. M. Gingrich, Sven Menke, J. Lauber, S. D. Talbot, D. Eatough, A. A. Carter, Ron Folman, F. Odorici, G. A. Snow, C. P. Ward, C. Hartmann, D. E. Plane, J. E. Pilcher, R. Lahmann, Stephen Hillier, Stan Bentvelsen, G. M. Dallavalle, S. Söldner-Rembold, L. Brigliadori, U. Müller, A. J. Martin, D. C. Imrie, P. Utzat, U. Ruppel, N. J. Oldershaw, John Allison, G. P. Siroli, P. G. Estabrooks, R. K. Keeler, M. R. Ingram, Christoph Schwick, H. M. Fischer, N. K. Watson, P. M. Watkins, W. R. Gibson, J. M. Roney, C. K. Hargrove, M. Fanti, B. T. Bouwens, Daniele Bonacorsi, R. G. Kellogg, James Pinfold, R. Perez-Ochoa, D. G. Fong, J. Gascon, J. Letts, Gideon Alexander, Paolo Capiluppi, Kiyotomo Kawagoe, Claire Shepherd-Themistocleous, R. M. Brown, Lorne Levinson, Csaba Hajdu, Robert McPherson, G. W. Wilson, P. S. Wells, V. Zacek, Richard Teuscher, Stefano Marcellini, A. Skillman, A. S. Turcot, M. Hauschild, K. Sachs, Mathieu Doucet, Tara Shears, R. D. Heuer, Fabrizio Fabbri, F. Fiedler, J. von Krogh, C. Markus, A. A. Faust, H. Mes, I. P. Duerdoth, Terry Richard Wyatt, Shlomo Dado, J. W. Gary, P. A. Hart, J. Schieck, D. S. Koetke, Stefan Kluth, Marcello Mannelli, Otmar Biebel, Silvia Arcelli, J. E. Bloomer, G. T. Jones, E. H. Vokurka, K. R. Hossain, T. Behnke, Satoshi Mihara, L. A. del Pozo, P. Scharff-Hansen, W. Mohr, Shlomit Tarem, S. Baumann, P. Hüntemeyer, Reda Tafirout, Klaus Kurt Desch, T. J. McMahon, M. J. Pearce, F. G. Oakham, Giora Mikenberg, B. Schmitt, M. Kolrep, B. Stockhausen, Paul Kyberd, E. A. Mckigney, A. Macchiolo, E. L. Barberio, R. K. Carnegie, A. Posthaus, D. Chrisman, G. D. Long, F. K. Loebinger, Hans-Christian Schultz-Coulon, M. Herndon, Volker Blobel, Randall Sobie, M. Gruwé, M. Bobinski, P. I. Kayal, G. D. Lafferty, C. M. Hawkes, W. P. Lai, J. A. Wilson, A. M. Smith, C. Dallapiccola, J. Steuerer, Ivor Fleck, Richard Nisius, S. W. O'Neale, Guenter Duckeck, D. M. Strom, K. J. Anderson, Marco Cuffiani, Joleen Pater, Norbert Wermes, Sherry Towers, T. Kawamoto, D. Lazic, M. A. Thomson, A. Klier, E. K. U. Gross, N. Altekamp, H. Voss, Stephen Lloyd, R. Rylko, R. Giacomelli, S. Orito, O. C. Cooke, P. Pfeifenschneider, M. Sproston, D. I. Futyan, R. J. Barlow, D. J. Miller, J. Goldberg, M. Hapke, B. Nellen, A. Oh, A. Macpherson, N. I. Geddes, Michael Hildreth, J. Patt, P. Poffenberger, D. E. Hutchcroft, André Schöning, Ehud Duchovni, N. L. Rodning, M. J. Oreglia, H. G. Evans, B. Poli, M. J. Goodrick, R. Howard, J. S. White, I. Cohen, S. A. Robins, D. L. Rees, J. R. Carter, G. N. Patrick, M. Jimack, Paolo Giacomelli, M. Hansroul, Gunter Wolf, K. Ackerstaff, D. Rigby, R. J. Hemingway, A. Joly, F. Scharf, German Martinez, Beatrix Dienes, S. M. Gascon-Shotkin, C. Burgard, C. Sbarra, R. J. Homer, A. Michelini, Matthew Evans, A. M. Rossi, C. Y. Chang, P. Taras, Michael Kobel, Allen Mincer, Satoshi Tanaka, T. Kobayashi, B. W. Kennedy, Julie Kirk, Ekg Sarkisyan, P. Jovanovic, P. W. Jeffreys, Austin Ball, Peter Krieger, P. Vikas, Alessandro Montanari, D. Lanske, M. Fierro, J. E.G. Edwards, S. R. Lautenschlager, H. A. Neal, O. Runolfsson, C. Beeston, Claudio Grandi, G. G. Hanson, G. Giacomelli, M. S. Dixit, Frans Meijers, A. Biguzzi, A. Rooke, J. G. Layter, P. E.L. Clarke, M. K. Jones, J. P. Martin, S. De Jong, A. N. Bell, P. Gagnon, A. Sittler, Peter Schleper, Zoltan Laszlo Trocsanyi, S. D. Bird, P. Schenk, D. Axen, A. Jawahery, Peter Sherwood, Alexander Wagner, J. Ludwig, K. Runge, P. Bock, Gideon Bella, H. J. Burckhart, Jacqueline Batley, Sachio Komamiya, Theodoros Geralis, E. Ros, A. T. Watson, I. J. Bloodworth, C. R. Jones, T. P. Kokott, Dave Charlton, R. Bürgin, T. Saeki, Yoram Rozen, R. Davis, M. Foucher, J. Grunhaus, D. Karlen, M. F. Turner-Watson, M. Morii, Peter R Hobson, Stefan Schmitt, D. Zer-Zion, P. Routenburg, P. Mättig, Shoji Asai, Daniel Lellouch, Takehiko Mori, K. Stoll, and Andris Skuja
Subjects: Physics, Stop squark, Top quark, Particle physics, Physics and Astronomy (miscellaneous), High Energy Physics::Lattice, High Energy Physics::Phenomenology, Top quark condensate, Bottom quark, Nuclear physics, Quark star, Neutralino, Up quark, High Energy Physics::Experiment, B meson, Nuclear Experiment, Engineering (miscellaneous), Particle Physics - Experiment
Abstract: Searches for a scalar top quark and a scalar bottom quark have been performed using a total data sample of 56.8 pb-1 at a centre-of-mass energy of 183 GeV collected with the OPAL detector at LEP. No candidate events were observed. Combining this result with those obtained at lower centre-of-mass energies, the 95% C.L. lower limit on the scalar top quark mass is 85.0 GeV if the mixing angle between the supersymmetric partners of the left- and right-handed states of the top quark is zero. The lower limit is 81.3 GeV, even if the scalar top quark decouples from the Z boson. These limits were obtained assuming that the scalar top quark decays into a charm quark and the lightest neutralino, and that the mass difference between the scalar top quark and the lightest neutralino is larger than 10 GeV. Assuming a relatively light scalar neutrino, The complementary decay mode of the scalar top quark in which it decays into a bottom quark, a charged lepton and a scalar neutrino was also studied. From a similar analysis, a mass limit on the light scalar bottom quark was set at 82.7 GeV for a mass difference between the scalar bottom quark and the lightest neutralino larger than 7 GeV, and at 84.0 GeV for the mass difference larger 10 GeV and the lightest neutralino heavier than 30 GeV. These limits were obtained assuming that the scalar bottom quark decays into a bottom quark and the lightest neutralino, and that a mixing angle between the supersymmetric partners of the left- and right-handed states of the bottom quark is zero. Searches for a scalar top quark and a scalar bottom quark have been performed using a total data sample of 56.8 pb-1 at a centre-of-mass energy of 183 GeV collected with the OPAL detector at LEP. No candidate events were observed. Combining this result with those obtained at lower centre-of-mass energies, the 95% C.L. lower limit on the scalar top quark mass is 85.0 GeV if the mixing angle between the supersymmetric partners of the left- and right-handed states of the top quark is zero. The lower limit is 81.3 GeV, even if the scalar top quark decouples from the Z boson. These limits were obtained assuming that the scalar top quark decays into a charm quark and the lightest neutralino, and that the mass difference between the scalar top quark and the lightest neutralino is larger than 10 GeV. Assuming a relatively light scalar neutrino, The complementary decay mode of the scalar top quark in which it decays into a bottom quark, a charged lepton and a scalar neutrino was also studied. From a similar analysis, a mass limit on the light scalar bottom quark was set at 82.7 GeV for a mass difference between the scalar bottom quark and the lightest neutralino larger than 7 GeV, and at 84.0 GeV for the mass difference larger 10 GeV and the lightest neutralino heavier than 30 GeV. These limits were obtained assuming that the scalar bottom quark decays into a bottom quark and the lightest neutralino, and that a mixing angle between the supersymmetric partners of the left- and right-handed states of the bottom quark is zero.
Published: 1999

41. Multi-photon production in e+e− collisions at =183 GeV

Author: K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, M. Bobinski, P. Bock, J. Böhme, M. Boutemeur, S. Braibant, P. Bright-Thomas, R.M. Brown, H.J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, C. Ciocca, P.E.L. Clarke, E. Clay, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, G.M. Dallavalle, R. Davis, S. De Jong, L.A. del Pozo, A. de Roeck, K. Desch, B. Dienes, M.S. Dixit, M. Doucet, J. Dubbert, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, H.G. Evans, F. Fabbri, A. Fanfani, M. Fanti, A.A. Faust, F. Fiedler, M. Fierro, H.M. Fischer, I. Fleck, R. Folman, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, C. Geich-Gimbel, T. Geralis, G. Giacomelli, P. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, G.G. Hanson, M. Hansroul, M. Hapke, C.K. Hargrove, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, S.J. Hillier, P.R. Hobson, A. Hocker, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, P. Igo-Kemenes, D.C. Imrie, K. Ishii, F.R. Jacob, A. Jawahery, H. Jeremie, M. Jimack, A. Joly, C.R. Jones, P. Jovanovic, T.R. Junk, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, P. Kyberd, G.D. Lafferty, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, R. Liebisch, B. List, C. Littlewood, A.W. Lloyd, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Liu, A. Macchiolo, A. Macpherson, M. Mannelli, S. Marcellini, C. Markopoulos, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, B. Poli, J. Polok, M. Przybycień, C. Rembser, H. Rick, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, K. Roscoe, A.M. Rossi, Y. Rozen, K. Runge, O. Runolfsson, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, B. Schmitt, S. Schmitt, A. Schöning, T. Schorner, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, R. Seuster, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, M. Sproston, A. Stahl, K. Stephens, J. Steuerer, K. Stoll, D. Strom, R. Ströhmer, R. Tafirout, S.D. Talbot, S. Tanaka, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, R. Van Kooten, P. Vannerem, M. Verzocchi, P. Vikas, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Luminosity (scattering theory), Photon, 010308 nuclear & particles physics, Branching fraction, Astrophysics::High Energy Astrophysical Phenomena, Resonance, Lambda, 01 natural sciences, 7. Clean energy, Excited state, 0103 physical sciences, High Energy Physics::Experiment, Invariant mass, 010306 general physics, Energy (signal processing)
Abstract: The process e+e- to gamma gamma (gamma) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 56.2 pb-1 taken at a centre-of-mass energy of 183 GeV. The measured cross-section agrees well with the expectation from QED. A fit to the angular distribution is used to obtain improved limits at 95% CL on the QED cut-off parameters: Lambda+ > 233 GeV and Lambda- > 265 GeV as well as a mass limit for an excited electron, M(e*) > 227 GeV assuming equal e*egamma and eegamma couplings. No evidence for resonance production is found in the invariant mass spectrum of photon pairs. Limits are obtained for the cross-section times branching ratio for a resonance decaying into two photons.
Published: 1998

42. Investigation of CP violation in $\mathrm{B^0} \rightarrow \mathrm{J}/\psi \mathrm{K^0_S}$ decays at LEP

Author: G. W. Wilson, Richard Teuscher, A. S. Turcot, M. Hauschild, C. Markopoulos, F. Fiedler, A. Biguzzi, A. Rooke, R. Bartoldus, A. Macpherson, C. Markus, I. J. Bloodworth, J. G. Layter, H. O. Ogren, R. Kowalewski, Christoph Geich-Gimbel, Yoram Rozen, M. Foucher, R. Davis, E. H. Vokurka, M. Kolrep, K. Stephens, H. M. Fischer, R. Howard, J. S. White, Gideon Alexander, Junichi Kanzaki, D. Karlen, M. Schumacher, E. Lefebvre, Paolo Capiluppi, P. G. Estabrooks, R. K. Keeler, A. Michelini, Vakhtang Kartvelishvili, P. Gagnon, F. Odorici, M. Fierro, V. Gibson, Randall Sobie, N. K. Watson, P. M. Watkins, Daniel Lellouch, J. E. Conboy, A. Fürtjes, J. Letts, S. R. Lautenschlager, G. D. Lafferty, Stefan Schmitt, L. Brigliadori, Shoji Asai, Takehiko Mori, R. W. Springer, P. Mättig, V. Zacek, A. Sittler, T. R. Junk, H. A. Neal, Lutz Feld, G. G. Hanson, Peter Schleper, I. Trigger, O. Runolfsson, K. Sachs, Zoltan Laszlo Trocsanyi, R. L. Coxe, D. R. Ward, T. Kress, John Allison, Shlomo Dado, N. J. Oldershaw, C. Dallapiccola, J. Goldberg, Silvia Arcelli, G. Giacomelli, I. Lawson, U. Ruppel, A. Hocker, D. Chrisman, G. D. Long, Volker Blobel, M. Boutemeur, F. S. Merritt, Matthias Schröder, B. Nellen, S. Yamashita, P. Igo-Kemenes, Guenter Duckeck, A. De Roeck, K. Ishii, H. Jeremie, P. Scharff-Hansen, Claudio Grandi, P. S. Wells, M. F. Turner-Watson, Peter R Hobson, S. W. O'Neale, M. S. Dixit, Frans Meijers, Georges Azuelos, E. Tsur, Stephen Lloyd, M. Thiergen, Giora Mikenberg, Terry Richard Wyatt, S. F. Ashby, K. J. Anderson, M. Verzocchi, K. W. Bell, Ekg Sarkisyan, S. D. Bird, J. Pálinkás, S. B. Anderson, S. M. Gascon-Shotkin, P. Szymanski, R. G. Kellogg, D. Zer-Zion, S. Baumann, E. A. Mckigney, Raimund Ströhmer, P. Routenburg, P. W. Jeffreys, J. Bechtluft, J. A. McKenna, Ehud Duchovni, J. C. Hill, O. Schaile, M. Jimack, P. E.L. Clarke, M. K. Jones, J. P. Martin, W. P. Lai, H. G. Evans, A. M. Smith, Csaba Hajdu, M. J. Goodrick, I. Cohen, S. Robertson, P. Poffenberger, J. M. Roney, S. De Jong, D. I. Futyan, W. J. McDonald, Stefano Marcellini, Gregor Herten, B. C. Shen, A. D. Schaile, Gabriella Pasztor, P. Vannerem, D. Lui, Anna Macchiolo, Stan Bentvelsen, Christoph Rembser, Satoshi Mihara, J. Grunhaus, D. Axen, Ikuo Ueda, D. M. Strom, Sven Menke, A. Jawahery, N. Altekamp, H. Voss, P. Vikas, T. Kobayashi, Siegfried Bethke, A. K. Honma, K. Stoll, Matthew Evans, A. M. Rossi, G. A. Snow, C. P. Ward, D. Lanske, W. M. Sang, W. G. Scott, J. E. Pilcher, I. Nakamura, S. Söldner-Rembold, A. J. Martin, Andris Skuja, Beatrix Dienes, R. J. Barlow, S. Petzold, Sachio Komamiya, R VanKooten, Theodoros Geralis, Peter Sherwood, Erez Etzion, C. Y. Chang, C. K. Hargrove, D. Glenzinski, A. T. Watson, Tara Shears, Tetsuro Mashimo, P. Taras, Dezso Horvath, M. J. Losty, Jean-Arcady Meyer, P. A. Hart, Michael Kobel, D. J. Miller, T. P. Kokott, A. Joly, Stefan Kluth, Shlomit Tarem, Allen Mincer, Marcello Fanti, T. Saeki, Alexander Wagner, J. Ludwig, Julie Kirk, K. Runge, P. Bock, Alessandra Fanfani, N. I. Geddes, Michael Hildreth, C. Sbarra, J. Lauber, N. L. Rodning, B. Poli, W. Gorn, B. Stockhausen, Paul Kyberd, F. K. Loebinger, U. Jost, S. A. Robins, R. Mir, J. Steuerer, Ivor Fleck, R. Hawkings, Joleen Pater, A. Klier, S. D. Talbot, R. Giacomelli, A. Oh, K. Ackerstaff, D. Eatough, James Pinfold, R. Perez-Ochoa, D. G. Fong, F. G. Oakham, B. Schmitt, J. Gascon, E. L. Barberio, Paolo Giacomelli, M. Hansroul, R. J. Hemingway, B. W. Kennedy, C. Burgard, P. Jovanovic, Austin Ball, Peter Krieger, Alessandro Montanari, R. J. Homer, J. W. Gary, D. S. Koetke, O. C. Cooke, P. Pfeifenschneider, Marcello Mannelli, J. Patt, André Schöning, O. Sahr, M. A. Thomson, H. Mes, I. P. Duerdoth, S. Braibant, P. Hüntemeyer, E. K. U. Gross, M. Sproston, C. Hartmann, D. E. Plane, Stephen Hillier, G. M. Dallavalle, Reda Tafirout, Klaus Kurt Desch, E. Torrence, W. R. Gibson, T. J. McMahon, C. Couyoumtzelis, R. M. Brown, Lorne Levinson, A. Skillman, R. K. Carnegie, M. Herndon, M. Bobinski, J. A. Wilson, F. Scharf, T. Behnke, C. M. Hawkes, German Martinez, Richard Nisius, B. List, D. Lazic, Marco Cuffiani, Dave Charlton, Daniele Bonacorsi, Claire Shepherd-Themistocleous, F. Wäckerle, D. M. Gingrich, J. von Krogh, R. Bürgin, A. A. Faust, M. Gruwé, L. A. del Pozo, G. Yekutieli, Robert McPherson, Mathieu Doucet, R. D. Heuer, A. A. Carter, Ron Folman, Fabrizio Fabbri, K. Nagai, P. Utzat, D. R. Rust, Gideon Bella, J. Schieck, A. M. Lee, E. von Törne, H. J. Burckhart, Jacqueline Batley, W. Mohr, A. Posthaus, C. R. Jones, R. Lahmann, D. C. Imrie, G. P. Siroli, Otmar Biebel, Christoph Schwick, P. I. Kayal, Kiyotomo Kawagoe, Norbert Wermes, Sherry Towers, T. Kawamoto, S. Orito, K. R. Hossain, S. Betts, M. Hapke, D. E. Hutchcroft, M. J. Oreglia, J. R. Carter, and G. N. Patrick
Subjects: Physics, Nuclear physics, Particle physics, Physics and Astronomy (miscellaneous), media_common.quotation_subject, Electron–positron annihilation, Hadron, Detector, CP violation, Engineering (miscellaneous), Asymmetry, media_common, Standard Model
Abstract: An investigation of CP violation was performed using a total of 24 candidates for B0→J/ψK0SB0→J/ψKS0 decay, with a purity of about 60%. These events were selected from 4.4 million hadronic Z0Z0 decays recorded by the OPAL detector at LEP. An analysis procedure, involving techniques to reconstruct the proper decay times and tag the produced b-flavours, B0B0 or B¯0B¯0 , has been developed to allow a first direct study of the time dependent CP asymmetry that, in the Standard Model, is sin2βsin⁡2β . The result is where the first error is statistical and the second systematic. This result is used to determine probabilities for different values of sin2βsin⁡2β in the physical region from −1−1 to +1.
Published: 1998

43. Determination of the production rate of D*0 mesons and of the ratio V/(V+P) in $$Z^0 \to c\bar c$$ decays

Author: K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K. J. Anderson, S. Anderson, S. Arcelli, S. Asai, S. F. Ashby, D. Axen, G. Azuelos, A. H. Ball, E. Barberio, R. J. Barlow, R. Bartoldus, J. R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K. W. Bell, G. Bella, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S. D. Bird, V. Blobel, I. J. Bloodworth, M. Bobinski, P. Bock, D. Bonacorsi, M. Boutemeur, S. Braibant, L. Brigliadori, R. M. Brown, H. J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R. K. Carnegie, A. A. Carter, J. R.Carter, C. Y. Chang, D. G. Charlton, D. Chrisman, P. E. L. Clarke, I. Cohen, J. E. Conboy, O. C. Cooke, C. Couyoumtzelis, R. L. Coxe, M. Cuffiani, S. Dado, C. Dallapiccola, G. M. Dallavalle, R. Davis, S. De Jong, L. A. del Pozo, A. de Roeck, K. Desch, B. Dienes, M. S. Dixit, M. Doucet, E. Duchovni, G. Duckeck, I. P. Duerdoth, D. Eatough, P. G. Estabrooks, E. Etzion, H. G. Evans, M. Evans, F. Fabbri, A. Fanfani, M. Fanti, A. A. Faust, L. Feld, F. Fiedler, M. Fierro, H. M. Fischer, I. Fleck, R. Folman, D. G. Fong, M. Foucher, A. Fürtjes, D. I. Futyan, P. Gagnon, J. W. Gary, J. Gascon, S. M. Gascon-Shotkin, N. I. Geddes, C. Geich-Gimbel, T. Geralis, G. Giacomelli, P. Giacomelli, R. Giacomelli, V. Gibson, W. R. Gibson, D. M. Gingrich, D. Glenzinski, J. Goldberg, M. J. Goodrick, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, C. Hajdu, G. G. Hanson, M. Hansroul, M. Hapke, C. K. Hargrove, P. A. Hart, C. Hartmann, M. Hauschild, C. M. Hawkes, R. Hawkings, R. J. Hemingway, M. Herndon, G. Herten, R. D. Heuer, M. D. Hildreth, J. C. Hill, S. J. Hillier, P. R. Hobson, A. Hocker, R. J. Homer, A. K. Honma, D. Horvath, K. R. Hossain, R. Howard, P. Hüntemeyer, D. E. Hutchcroft, P. Igo-Kemenes, D. C. Imrie, K. Ishii, A. Jawahery, P. W. Jeffreys, H. Jeremie, M. Jimack, A. Joly, C. R. Jones, M. Jones, U. Jost, P. Jovanovic, T. R. Junk, J. Kanzaki, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P. I. Kayal, R. K. Keeler, R. G. Kellogg, B. W. Kennedy, J. Kirk, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D. S. Koetke, T. P. Kokott, M. Kolrep, S. Komamiya, R. V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, P. Kyberd, G. D. Lafferty, R. Lahmann, W. P. Lai, D. Lanske, J. Lauber, S. R. Lautenschlager, I. Lawson, J. G. Layter, D. Lazic, A. M. Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, B. List, S. L. Lloyd, F. K. Loebinger, G. D. Long, M. J. Losty, J. Ludwig, D. Lui, A. Macchiolo, A. Macpherson, M. Mannelli, S. Marcellini, C. Markopoulos, C. Markus, A. J. Martin, J. P. Martin, G. Martinez, T. Mashimo, P. Mättig, W. J. McDonald, J. McKenna, E. A. Mckigney, T. J. McMahon, R. A. McPherson, F. Meijers, S. Menke, F. S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D. J. Miller, A. Mincer, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H. A. Neal, B. Nellen, R. Nisius, S. W. O’Neale, F. G. Oakham, F. Odorici, H. O. Ogren, A. Oh, N. J. Oldershaw, M. J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J. R. Pater, G. N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J. E. Pilcher, J. Pinfold, D. E. Plane, P. Poffenberger, B. Poli, A. Posthaus, C. Rembser, S. Robertson, S. A. Robins, N. Rodning, J. M. Roney, A. Rooke, A. M. Rossi, P. Routenburg, Y. Rozen, K. Runge, O. Runolfsson, U. Ruppel, D. R. Rust, K. Sachs, T. Saeki, O. Sahr, W. M. Sang, E. K. G. Sarkisyan, C. Sbarra, A. D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, P. Schleper, B. Schmitt, S. Schmitt, A. Schöming, M. Schröder, M. Schumacher, C. Schwick, W. G. Scott, T. G. Shears, B. C. Shen, C. H. Shepherd-Themistocleous, P. Sherwood, G. P. Siroli, A. Sittler, A. Skillman, A. Skuja, A. M. Smith, G. A. Snow, R. Sobie, S. Söldner-Rembold, R. W. Springer, M. Sproston, K. Stephens, J. Steuerer, B. Stockhausen, K. Stoll, D. Strom, R. Ströhmer, P. Szymanski, R. Tafirout, S. D. Talbot, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, M. A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A. S. Turcot, M. F. Turner-Watson, I. Ueda, P. Utzat, R. Van Kooten, P. Vannerem, M. Verzocchi, P. Vikas, E. H. Vokurka, H. Voss, F. Wäckerle, A. Wagner, C. P. Ward, D. R. Ward, P. M. Watkins, A. T. Watson, N. K. Watson, P. S. Wells, N. Wermes, J. S. White, G. W. Wilson, J. A. Wilson, T. R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Systematic error, Physics, Particle physics, Annihilation, Physics and Astronomy (miscellaneous), Meson, Electron–positron annihilation, High Energy Physics::Phenomenology, Hadron, Nuclear physics, Pseudoscalar, Excited state, High Energy Physics::Experiment, Nuclear Experiment, Engineering (miscellaneous), Production rate
Abstract: In e+e2212 collisions at centre-of-mass energies around 91 GeV, D*0 mesons have been reconstructed using data collected with the OPAL detector at LEP. The hadronisation fraction has been measured to be f(c→D*0)=0.218±0.054±0.045±0.007, where the errors correspond to the statistical and systematic errors specific to this analysis, and to systematic uncertainties from externally measured branching fractions, respectively. Together with previous OPAL measurements of the hadronisation fractions of other charmed mesons, this value is used to investigate the relative production of observed vector and pseudoscalar charmed mesons in $Z^0 \to c\bar c$ decays. The production ratio is determined to be PeffV = V/(V+P)=0.57±0.05. The relative primary production of vector and pseudoscalar mesons, Pvrim, is studied in the context of the production and decay of orbitally excited charmed resonances. The first measurement of the inclusive Ds*+ production rate in hadronic Z0 decays is presented.
Published: 1998

44. An upper limit for the $\tau$ –neutrino mass from $\tau\rightarrow 5\pi^{\pm}\nu_{\tau}$ decays

Author: R. Bartoldus, H. M. Fischer, H. O. Ogren, Christoph Geich-Gimbel, P. G. Bright-Thomas, N. Altekamp, H. Voss, Gideon Bella, M. Schumacher, E. Lefebvre, S. B. Anderson, D. J. Miller, Vakhtang Kartvelishvili, S. L. Lloyd, F. Odorici, Otmar Biebel, P. I. Kayal, A. J. Martin, Norbert Wermes, Sherry Towers, T. Kawamoto, J. E. Conboy, A. Fürtjes, S. Orito, H. A. Neal, B. C. Shen, S. W. O'Neale, H. J. Burckhart, Jacqueline Batley, Stan Bentvelsen, J. A. McKenna, Daniel Lellouch, Takehiko Mori, J. Grunhaus, P. Gagnon, J. Allison, Siegfried Bethke, A. K. Honma, W. G. Scott, I. Nakamura, Silvia Arcelli, R. J. Hemingway, B. W. Kennedy, P. Jovanovic, P. Mättig, R. Kowalewski, Austin Ball, Peter Krieger, C. K. Hargrove, Claudia Ciocca, M. Boutemeur, F. S. Merritt, Alessandro Montanari, S. A. Robins, H. Mes, I. P. Duerdoth, A. Sittler, R. Mir, Zoltan Laszlo Trocsanyi, Matthias Schröder, J. W. Gary, K. J. Anderson, R. Hawkings, Raimund Ströhmer, J. R. Carter, P. Igo-Kemenes, T. Schorner, M. Thiergen, S. Braibant, Gideon Alexander, Paolo Capiluppi, S. Baumann, K. Ishii, H. Jeremie, S. Betts, M. Hapke, Stefan Schmitt, J. Bechtluft, R. Liebisch, K. Ackerstaff, E. A. Mckigney, James Pinfold, R. Perez-Ochoa, R. Seuster, M. J. Oreglia, G. Duckeck, C. R. Jones, F. G. Oakham, D. Glenzinski, B. Schmitt, E. L. Barberio, G. N. Patrick, G. Mikenberg, P. Hüntemeyer, J. Gascon, V. Gibson, O. Schaile, Dezso Horvath, M. J. Losty, Ehud Duchovni, R. J. Barlow, Jean-Arcady Meyer, A. D. Schaile, Gabriella Pasztor, V. Zacek, K. Roscoe, W.J. McDonald, J. Lauber, S. Robertson, M. F. Turner-Watson, F. Scharf, M. Fierro, M. Jimack, Ekg Sarkisyan, R. G. Kellogg, T. Kobayashi, P. Vannerem, German Martinez, N. K. Watson, Tara Shears, D. Lui, S. M. Gascon-Shotkin, Shoji Asai, A. Michelini, Beatrix Dienes, Peter R Hobson, D. S. Koetke, Reda Tafirout, Klaus Kurt Desch, G. D. Lafferty, D. I. Futyan, Sven Menke, Marcello Mannelli, I. J. Bloodworth, E. Torrence, Richard Teuscher, A. S. Turcot, Dave Charlton, D. Zer-Zion, K. Stoll, G. A. Snow, Andris Skuja, J. Goldberg, Claire Shepherd-Themistocleous, Stefano Marcellini, F. Fiedler, B. Nellen, C. P. Ward, S. D. Talbot, S. Petzold, C. Y. Chang, E. Clay, Sachio Komamiya, R. L. Coxe, M. Przybzien, M. A. Thomson, Theodoros Geralis, G. W. Wilson, P. G. Estabrooks, R. K. Keeler, W. M. Sang, S. Söldner-Rembold, Tetsuro Mashimo, Yoram Rozen, P. Taras, A. Hocker, R. Bürgin, P. Vikas, E. K. U. Gross, D. Eatough, D. Chrisman, G. D. Long, D. Lanske, J. Letts, A. A. Faust, W. R. Gibson, Volker Blobel, S. R. Lautenschlager, M. Sproston, T. P. Kokott, P. M. Watkins, H. G. Evans, M. Kolrep, W. Gorn, T. Saeki, S. D. Bird, I. Cohen, Georges Azuelos, T. Behnke, E. Tsur, J. Polok, A. Joly, D. Karlen, O. Runolfsson, Christoph Rembser, Alessandra Fanfani, D. Axen, R. Davis, Satoru Yamashita, M. Verzocchi, K. W. Bell, A. M. Rossi, K. Sachs, Shlomo Dado, A. Jawahery, A. Macchiolo, Claudio Grandi, P. Scharff-Hansen, J. Pálinkás, R. M. Brown, C. M. Hawkes, C. Sbarra, Lorne Levinson, Stefan Kluth, Peter Sherwood, Alexander Wagner, Shlomit Tarem, J. M. Roney, J. C. Hill, F. R. Jacob, J. Ludwig, K. Runge, Richard Nisius, A. M. Smith, P. Bock, B. List, Marco Cuffiani, S. F. Ashby, J. Schieck, W. Mohr, C. Hartmann, D. E. Plane, Stephen Hillier, Paul Kyberd, F. K. Loebinger, G. M. Dallavalle, Michael Hildreth, J. Steuerer, Ivor Fleck, N. L. Rodning, B. Poli, Joleen Pater, A. Klier, P. Poffenberger, Satoshi Mihara, K. Stephens, C. Littlewood, G. Yekutieli, T. R. Junk, I. Trigger, D. R. Ward, T. Kress, A. A. Carter, Ron Folman, T. J. McMahon, C. Couyoumtzelis, J. Dubbert, R. K. Carnegie, M. Herndon, M. Bobinski, J. A. Wilson, J. Böhme, P. E.L. Clarke, J. P. Martin, D. Lazic, S. De Jong, H. Rick, J. von Krogh, M. Gruwé, L. A. del Pozo, G. G. Hanson, G. Giacomelli, I. Lawson, A. De Roeck, M. Kobel, M. S. Dixit, Frans Meijers, O. C. Cooke, P. Pfeifenschneider, J. Patt, André Schöning, O. Sahr, A. Biguzzi, J. G. Layter, Paolo Giacomelli, M. Hansroul, C. Burgard, R. J. Homer, Achim Stahl, Kiyotomo Kawagoe, R. Van Kooten, K. R. Hossain, D. C. Imrie, G. P. Siroli, Christoph Schwick, F. Wäckerle, D. M. Gingrich, D. M. Strom, M. Fanti, Robert McPherson, Mathieu Doucet, R. D. Heuer, Fabrizio Fabbri, K. Nagai, Shigenori Tanaka, D. R. Rust, A. M. Lee, E. von Törne, P. S. Wells, Terry Richard Wyatt, A. T. Watson, A. Macpherson, R. J. Sobie, R. Howard, J. S. White, Gregor Herten, J. E. Pilcher, A. W. Lloyd, M. Hauschild, and C. Markopoulos
Subjects: Physics, Particle physics, Energy distribution, Physics and Astronomy (miscellaneous), High Energy Physics::Phenomenology, Particle identification, Nuclear physics, Tau neutrino, Pi, High Energy Physics::Experiment, Invariant mass, Limit (mathematics), Engineering (miscellaneous), ALEPH experiment
Abstract: An upper limit for the $\tau$–neutrino mass has been determined from the decay $\tau\rightarrow 5\pi^{\pm}\nu_{\tau}$ using data collected with the OPAL detector from 1991 to 1995 in $\rm e^{+}e^{-}$ collisions at $\sqrt{s}\approx M_\mathrm{Z}$. A limit of 43.2 MeV at 95% CL is obtained using a two–dimensional method in the $5\pi$ invariant mass and energy distribution from 22 selected events. Combining this result with OPAL's previously published measurement using $\rm \tau^{+}\tau^{-}\rightarrow 3h^{\pm}\bar{\nu}_{\tau}+3h^{\mp}\nu_{\tau}$ decays, a new combined limit of \(m_{\nu_{\tau}}
Published: 1998

45. Bose-Einstein correlations of three charged pions in hadronic Z $^{\bf 0}$ decays

Author: Erez Etzion, Stefan Kluth, Shlomit Tarem, S. A. Robins, T. Schorner, J. Grunhaus, Tara Shears, R. Liebisch, K. Ackerstaff, Sachio Komamiya, Theodoros Geralis, A. T. Watson, T. P. Kokott, T. Saeki, Alessandra Fanfani, G. Yekutieli, Otmar Biebel, G. G. Hanson, W. R. Gibson, H. M. Fischer, M. Przybycień, M. F. Turner-Watson, Peter R Hobson, J. Goldberg, D. Zer-Zion, M. Fierro, B. Nellen, S. R. Lautenschlager, A. A. Carter, Ron Folman, G. Giacomelli, I. Lawson, M. Boutemeur, F. S. Merritt, H. G. Evans, Gideon Bella, H. J. Burckhart, I. Cohen, Christoph Rembser, A. De Roeck, M. Kobel, O. Runolfsson, M. S. Dixit, Frans Meijers, J. Letts, R. M. Brown, Lorne Levinson, Matthias Schröder, A. W. Lloyd, P. I. Kayal, P. Gagnon, W. M. Sang, Jacqueline Batley, Claudio Grandi, M. Thiergen, J. Bechtluft, J. A. McKenna, Satoshi Mihara, Ekg Sarkisyan, P. E.L. Clarke, S. Yamashita, Kiyotomo Kawagoe, J. P. Martin, Ehud Duchovni, K. Sachs, K. Roscoe, J. von Krogh, M. Hauschild, C. Markopoulos, Norbert Wermes, Sherry Towers, S. De Jong, A. Sittler, Shlomo Dado, T. Kawamoto, Zoltan Laszlo Trocsanyi, P. Vikas, M. Jimack, Claire Shepherd-Themistocleous, P. Igo-Kemenes, P. G. Estabrooks, N. K. Watson, M. Gruwé, Reda Tafirout, Klaus Kurt Desch, A. J. Martin, H. Rick, R. Bartoldus, G. W. Wilson, A. Joly, D. Lanske, S. Orito, L. A. del Pozo, Claudia Ciocca, K. Ishii, H. Jeremie, A. Michelini, E. Torrence, Achim Stahl, E. Clay, H. O. Ogren, S. Betts, M. Hapke, Giora Mikenberg, Satoshi Tanaka, T. Kobayashi, P. M. Watkins, Georges Azuelos, K. Stephens, S. D. Bird, C. Sbarra, F. R. Jacob, E. Tsur, T. J. McMahon, C. Couyoumtzelis, J. Dubbert, R. K. Carnegie, M. Herndon, C. K. Hargrove, K. Nagai, Michael Hildreth, M. Bobinski, J. A. Wilson, S. F. Ashby, K. R. Hossain, N. L. Rodning, J. Böhme, A. D. Schaile, Gabriella Pasztor, C. Hartmann, Christoph Geich-Gimbel, P. S. Wells, Vakhtang Kartvelishvili, P. Vannerem, M. Verzocchi, K. W. Bell, J. Pálinkás, J. C. Hill, O. Schaile, B. Poli, D. Axen, A. Jawahery, Stefan Schmitt, C. Littlewood, A. Biguzzi, D. E. Plane, R. L. Coxe, Silvia Arcelli, M. J. Oreglia, Stephen Hillier, D. Lui, Paul Kyberd, F. K. Loebinger, J. G. Layter, J. E. Conboy, G. M. Dallavalle, A. Fürtjes, James Pinfold, R. Perez-Ochoa, R. Seuster, W. J. McDonald, B. C. Shen, V. Gibson, D. Lazic, G. A. Snow, C. P. Ward, A. Hocker, Terry Richard Wyatt, D. R. Rust, C. R. Jones, J. Steuerer, Ivor Fleck, J. R. Carter, G. N. Patrick, Siegfried Bethke, A. K. Honma, W. G. Scott, Randall Sobie, S. M. Gascon-Shotkin, S. Söldner-Rembold, S. Baumann, S. Robertson, Joleen Pater, D. Chrisman, G. D. Long, Peter Sherwood, G. D. Lafferty, Gregor Herten, T. R. Junk, S. W. O'Neale, I. Nakamura, A. Klier, E. A. Mckigney, Volker Blobel, Alexander Wagner, I. Trigger, K. J. Anderson, Sven Menke, A. M. Rossi, J. Ludwig, Raimund Ströhmer, D. R. Ward, N. Altekamp, H. Voss, K. Runge, T. Kress, P. Bock, D. Glenzinski, Dezso Horvath, M. J. Losty, J. M. Roney, J. Lauber, Stephen Lloyd, J. E. Pilcher, Jean-Arcady Meyer, Dave Charlton, D. I. Futyan, R. J. Barlow, A. M. Lee, D. J. Miller, J. Gascon, P. Poffenberger, D. C. Imrie, John Allison, D. M. Strom, E. von Törne, R. Bürgin, S. D. Talbot, Guenter Duckeck, Paolo Giacomelli, R. Kowalewski, D. Eatough, G. P. Siroli, Shoji Asai, M. Hansroul, Christoph Schwick, Beatrix Dienes, C. Burgard, R. G. Kellogg, M. Fanti, Gideon Alexander, R. J. Homer, Paolo Capiluppi, S. B. Anderson, Daniel Lellouch, R. Mir, C. Y. Chang, R. Hawkings, A. Macpherson, Stefano Marcellini, Richard Keeler, O. C. Cooke, J. W. Gary, Takehiko Mori, P. Taras, P. Pfeifenschneider, Robert McPherson, R. Howard, D. S. Koetke, J. S. White, Mathieu Doucet, J. Patt, André Schöning, P. Mättig, R. D. Heuer, Fabrizio Fabbri, Marcello Mannelli, O. Sahr, Stan Bentvelsen, R. Van Kooten, K. Stoll, V. Zacek, F. Wäckerle, Andris Skuja, D. M. Gingrich, S. Petzold, Tetsuro Mashimo, Richard Teuscher, A. S. Turcot, F. Fiedler, F. G. Oakham, W. Gorn, B. Schmitt, E. L. Barberio, M. Kolrep, I. J. Bloodworth, P. Scharff-Hansen, R. J. Hemingway, B. W. Kennedy, P. Jovanovic, Austin Ball, Yoram Rozen, Peter Krieger, Alessandro Montanari, A. M. Smith, J. Polok, D. Karlen, A. A. Faust, T. Behnke, A. Macchiolo, C. M. Hawkes, Richard Nisius, B. List, Marco Cuffiani, H. Mes, I. P. Duerdoth, S. Braibant, P. Hüntemeyer, R. Davis, P. G. Bright-Thomas, M. Schumacher, E. Lefebvre, F. Odorici, H. A. Neal, F. Scharf, German Martinez, M. A. Thomson, E. K. U. Gross, M. Sproston, J. Schieck, and W. Mohr
Subjects: Physics, Particle physics, Physics and Astronomy (miscellaneous), High Energy Physics::Phenomenology, Nuclear Theory, Hadron, Bose–Einstein correlations, Lambda, Nuclear physics, Near threshold, Pion, Coulomb, High Energy Physics::Experiment, Nuclear Experiment, Coulomb effect, Engineering (miscellaneous)
Abstract: Bose-Einstein Correlations (BEC) of three identical charged pions were studied in $4 \times 10^6$ hadronic ${\rm Z}^0$ decays recorded with the OPAL detector at LEP. The genuine three-pion correlations, corrected for the Coulomb effect, were separated from the known two-pion correlations by a new subtraction procedure. A significant genuine three-pion BEC enhancement near threshold was observed having an emitter source radius of $r_3 = 0.580 \pm 0.004 \mbox{ (stat.)} \pm 0.029 \mbox{ (syst.)} \mbox{ fm}$ and a strength of $\lambda_3 = 0.504 \pm 0.010 \mbox{ (stat.)}\pm 0.041 \mbox{ (syst.)}$ . The Coulomb correction was found to increase the $\lambda_3$ value by $\sim $ 9% and to reduce $r_3$ by $\sim $ 6%. The measured $\lambda_3$ corresponds to a value of $0.707 \pm 0.014 \mbox{ (stat.)} \pm 0.078 \mbox{ (syst.)}$ when one takes into account the three-pion sample purity. A relation between the two-pion and the three-pion source parameters is discussed.
Published: 1998

46. An upper limit on the anomalous magnetic moment of the τ lepton

Author: K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, M. Bobinski, P. Bock, D. Bonacorsi, M. Boutemeur, S. Braibant, L. Brigliadori, R.M. Brown, H.J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, P.E.L. Clarke, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, C. Dallapiccola, G.M. Dallavalle, R. Davis, S. De Jong, L.A. del Pozo, A. de Roeck, K. Desch, B. Dienes, M.S. Dixit, M. Doucet, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, H.G. Evans, M. Evans, F. Fabbri, A. Fanfani, M. Fanti, A.A. Faust, L. Feld, F. Fiedler, M. Fierro, H.M. Fischer, I. Fleck, R. Folman, D.G. Fong, M. Foucher, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, N.I. Geddes, C. Geich-Gimbel, T. Geralis, G. Giacomelli, P. Giacomelli, R. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, M.J. Goodrick, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, C.K. Hargrove, P.A. Hart, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, S.J. Hillier, P.R. Hobson, A. Hocker, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, D.E. Hutchcroft, P. Igo-Kemenes, D.C. Imrie, K. Ishii, A. Jawahery, P.W. Jeffreys, H. Jeremie, M. Jimack, A. Joly, C.R. Jones, M. Jones, U. Jost, P. Jovanovic, T.R. Junk, J. Kanzaki, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, J. Kirk, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, P. Kyberd, G.D. Lafferty, R. Lahmann, W.P. Lai, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, B. List, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Lui, A. Macchiolo, A. Macpherson, M. Mannelli, S. Marcellini, C. Markopoulos, C. Markus, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, A. Mincer, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Oh, N.J. Oldershaw, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, B. Poli, A. Posthaus, C. Rembser, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, A. Rooke, A.M. Rossi, P. Routenburg, Y. Rozen, K. Runge, O. Runolfsson, U. Ruppel, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, P. Schleper, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, R.P.B. Sieberg, G.P. Siroli, A. Sittler, A. Skillman, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, R.W. Springer, M. Sproston, K. Stephens, J. Steuerer, B. Stockhausen, K. Stoll, D. Strom, R. Ströhmer, P. Szymanski, R. Tafirout, S.D. Talbot, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, I. Ueda, P. Utzat, R. Van Kooten, P. Vannerem, M. Verzocchi, P. Vikas, E.H. Vokurka, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Anomalous magnetic dipole moment, 010308 nuclear & particles physics, Form factor (quantum field theory), 01 natural sciences, High Energy Physics - Experiment, Dipole, 0103 physical sciences, Magnetic form factor, Radiative transfer, Vertex (curve), High Energy Physics::Experiment, Production (computer science), 010306 general physics, Particle Physics - Experiment, Lepton
Abstract: Using radiative Z^0 -> \tau^+ \tau^- \gamma events collected with the OPAL detector at LEP at \sqrt{s}= M_Z during 1990-95, a direct study of the electromagnetic current at the \tau\gamma vertex has been performed in terms of the anomalous magnetic form factor F_2 of the \tau lepton. The analysis is based on a data sample of 1429 e^+ e^- -> \tau^+ \tau^- \gamma events which are examined for a deviation from the expectation with F_2 = 0. From the non-observation of anomalous \tau^+ \tau^- \gamma production a limit of -0.068 < F_2 < 0.065 is obtained. This can also be interpreted as a limit on the electric dipole form factor F_3 as -3.8 x 10^-16 e-cm < eF_3 < 3.6 x 10^-16 e-cm. The above ranges are valid at the 95% confidence level., Comment: 20 pages, LaTeX, uses a4p.sty, 4 eps figures included, submitted to Phys. Lett. B
Published: 1998

47. Search for an excess in the production of four-jet events from e+e− collisions at =130–184 GeV

Author: K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K.J. Anderson, S. Anderson, S. Arcelli, S. Asai, S.F. Ashby, D. Axen, G. Azuelos, A.H. Ball, E. Barberio, R.J. Barlow, R. Bartoldus, J.R. Batley, S. Baumann, J. Bechtluft, T. Behnke, K.W. Bell, G. Bella, S. Bentvelsen, S. Bethke, S. Betts, O. Biebel, A. Biguzzi, S.D. Bird, V. Blobel, I.J. Bloodworth, M. Bobinski, P. Bock, D. Bonacorsi, M. Boutemeur, S. Braibant, L. Brigliadori, R.M. Brown, H.J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R.K. Carnegie, A.A. Carter, J.R. Carter, C.Y. Chang, D.G. Charlton, D. Chrisman, P.E.L. Clarke, I. Cohen, J.E. Conboy, O.C. Cooke, C. Couyoumtzelis, R.L. Coxe, M. Cuffiani, S. Dado, C. Dallapiccola, G.M. Dallavalle, R. Davis, S. De Jong, L.A. del Pozo, A. de Roeck, K. Desch, B. Dienes, M.S. Dixit, M. Doucet, E. Duchovni, G. Duckeck, I.P. Duerdoth, D. Eatough, P.G. Estabrooks, E. Etzion, H.G. Evans, M. Evans, F. Fabbri, A. Fanfani, M. Fanti, A.A. Faust, L. Feld, F. Fiedler, M. Fierro, H.M. Fischer, I. Fleck, R. Folman, D.G. Fong, M. Foucher, A. Fürtjes, D.I. Futyan, P. Gagnon, J.W. Gary, J. Gascon, S.M. Gascon-Shotkin, N.I. Geddes, C. Geich-Gimbel, T. Geralis, G. Giacomelli, P. Giacomelli, R. Giacomelli, V. Gibson, W.R. Gibson, D.M. Gingrich, D. Glenzinski, J. Goldberg, M.J. Goodrick, W. Gorn, C. Grandi, E. Gross, J. Grunhaus, M. Gruwé, C. Hajdu, G.G. Hanson, M. Hansroul, M. Hapke, C.K. Hargrove, P.A. Hart, C. Hartmann, M. Hauschild, C.M. Hawkes, R. Hawkings, R.J. Hemingway, M. Herndon, G. Herten, R.D. Heuer, M.D. Hildreth, J.C. Hill, S.J. Hillier, P.R. Hobson, A. Hocker, R.J. Homer, A.K. Honma, D. Horváth, K.R. Hossain, R. Howard, P. Hüntemeyer, D.E. Hutchcroft, P. Igo-Kemenes, D.C. Imrie, K. Ishii, A. Jawahery, P.W. Jeffreys, H. Jeremie, M. Jimack, A. Joly, C.R. Jones, M. Jones, U. Jost, P. Jovanovic, T.R. Junk, J. Kanzaki, D. Karlen, V. Kartvelishvili, K. Kawagoe, T. Kawamoto, P.I. Kayal, R.K. Keeler, R.G. Kellogg, B.W. Kennedy, J. Kirk, A. Klier, S. Kluth, T. Kobayashi, M. Kobel, D.S. Koetke, T.P. Kokott, M. Kolrep, S. Komamiya, R.V. Kowalewski, T. Kress, P. Krieger, J. von Krogh, P. Kyberd, G.D. Lafferty, R. Lahmann, W.P. Lai, D. Lanske, J. Lauber, S.R. Lautenschlager, I. Lawson, J.G. Layter, D. Lazic, A.M. Lee, E. Lefebvre, D. Lellouch, J. Letts, L. Levinson, B. List, S.L. Lloyd, F.K. Loebinger, G.D. Long, M.J. Losty, J. Ludwig, D. Lui, A. Macchiolo, A. Macpherson, M. Mannelli, S. Marcellini, C. Markopoulos, C. Markus, A.J. Martin, J.P. Martin, G. Martinez, T. Mashimo, P. Mättig, W.J. McDonald, J. McKenna, E.A. Mckigney, T.J. McMahon, R.A. McPherson, F. Meijers, S. Menke, F.S. Merritt, H. Mes, J. Meyer, A. Michelini, S. Mihara, G. Mikenberg, D.J. Miller, A. Mincer, R. Mir, W. Mohr, A. Montanari, T. Mori, K. Nagai, I. Nakamura, H.A. Neal, B. Nellen, R. Nisius, S.W. O'Neale, F.G. Oakham, F. Odorici, H.O. Ogren, A. Oh, N.J. Oldershaw, M.J. Oreglia, S. Orito, J. Pálinkás, G. Pásztor, J.R. Pater, G.N. Patrick, J. Patt, R. Perez-Ochoa, S. Petzold, P. Pfeifenschneider, J.E. Pilcher, J. Pinfold, D.E. Plane, P. Poffenberger, B. Poli, A. Posthaus, C. Rembser, S. Robertson, S.A. Robins, N. Rodning, J.M. Roney, A. Rooke, A.M. Rossi, P. Routenburg, Y. Rozen, K. Runge, O. Runolfsson, U. Ruppel, D.R. Rust, K. Sachs, T. Saeki, O. Sahr, W.M. Sang, E.K.G. Sarkisyan, C. Sbarra, A.D. Schaile, O. Schaile, F. Scharf, P. Scharff-Hansen, J. Schieck, P. Schleper, B. Schmitt, S. Schmitt, A. Schöning, M. Schröder, M. Schumacher, C. Schwick, W.G. Scott, T.G. Shears, B.C. Shen, C.H. Shepherd-Themistocleous, P. Sherwood, G.P. Siroli, A. Sittler, A. Skillman, A. Skuja, A.M. Smith, G.A. Snow, R. Sobie, S. Söldner-Rembold, R.W. Springer, M. Sproston, K. Stephens, J. Steuerer, B. Stockhausen, K. Stoll, D. Strom, R. Ströhmer, P. Szymanski, R. Tafirout, S.D. Talbot, P. Taras, S. Tarem, R. Teuscher, M. Thiergen, M.A. Thomson, E. von Törne, E. Torrence, S. Towers, I. Trigger, Z. Trócsányi, E. Tsur, A.S. Turcot, M.F. Turner-Watson, I. Ueda, P. Utzat, R. Van Kooten, P. Vannerem, M. Verzocchi, P. Vikas, E.H. Vokurka, H. Voss, F. Wäckerle, A. Wagner, C.P. Ward, D.R. Ward, P.M. Watkins, A.T. Watson, N.K. Watson, P.S. Wells, N. Wermes, J.S. White, G.W. Wilson, J.A. Wilson, T.R. Wyatt, S. Yamashita, G. Yekutieli, V. Zacek, and D. Zer-Zion
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Aleph, 010308 nuclear & particles physics, FOS: Physical sciences, Jet (particle physics), 01 natural sciences, High Energy Physics - Experiment, Standard Model, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, High Energy Physics::Experiment, Production (computer science), 010306 general physics, Particle Physics - Experiment
Abstract: Events with four distinct jets from e^+e^- collisions, collected by the OPAL detector at centre-of-mass energies between 130 and 184 GeV, are analysed for a peak in the sum of dijet masses. This search is motivated by the ALEPH Collaboration's observation of a clear excess of events with dijet mass sums close to 105 GeV in data taken at centre-of-mass energies of 130 and 136 GeV in 1995. We have observed no significant excess of four-jet events compared to the Standard Model expectation for any dijet mass sum at any energy. Our observation is inconsistent with the excess observed by ALEPH in 1995. Upper limits are determined on the production cross-section as a function of the dijet mass sum., Comment: 24 pages, LaTeX, uses a4p.sty, 5 eps figures included, submitted to Physics Letters B
Published: 1998

48. Production of ${\rm f_0}(980)$ , ${\rm f}_2(1270)$ and $\phi(1020)$ in hadronic ${\rm Z}^0$ decay

Author: S. Betts, S. Yamashita, M. Hapke, J. Letts, P. Igo-Kemenes, D. E. Hutchcroft, K. Ishii, H. Jeremie, K. Sachs, A. Biguzzi, A. Rooke, J. G. Layter, Paolo Giacomelli, P. S. Wells, M. J. Oreglia, Shlomo Dado, O. Schaile, M. Hansroul, S. R. Lautenschlager, Terry Richard Wyatt, R. Lahmann, D. C. Imrie, L. Brigliadori, Sven Menke, Gideon Bella, T. Behnke, J. R. Carter, C. Burgard, G. N. Patrick, Stefan Schmitt, C. Hartmann, D. E. Plane, Stephen Hillier, G. M. Dallavalle, H. J. Burckhart, Jacqueline Batley, H. M. Fischer, R. J. Hemingway, Giora Mikenberg, S. F. Ashby, R. W. Springer, A. Macpherson, G. P. Siroli, Otmar Biebel, R. J. Homer, B. W. Kennedy, Christoph Schwick, A. Macchiolo, Tara Shears, P. Jovanovic, C. R. Jones, W. M. Sang, Austin Ball, O. Runolfsson, N. J. Oldershaw, J. Lauber, C. M. Hawkes, Peter Krieger, P. A. Hart, Kiyotomo Kawagoe, S. W. O'Neale, Georges Azuelos, Shoji Asai, G. G. Hanson, G. Yekutieli, E. Tsur, M. Boutemeur, F. S. Merritt, K. J. Anderson, M. Verzocchi, Richard Nisius, Alessandro Montanari, Richard Teuscher, A. D. Schaile, K. W. Bell, P. I. Kayal, J. Pálinkás, Gabriella Pasztor, H. A. Neal, R. Howard, M. F. Turner-Watson, J. S. White, A. S. Turcot, F. Fiedler, G. Giacomelli, J. C. Hill, B. List, I. Lawson, Daniel Lellouch, C. Y. Chang, W. J. McDonald, Dave Charlton, A. De Roeck, P. Vannerem, U. Ruppel, A. A. Carter, Marco Cuffiani, Norbert Wermes, B. C. Shen, Peter R Hobson, H. Mes, Ron Folman, P. Taras, G. W. Wilson, D. Zer-Zion, D. Lui, K. R. Hossain, R. Bürgin, Michael Kobel, Siegfried Bethke, A. K. Honma, M. Hauschild, C. Markopoulos, U. Jost, R. Mir, R. Hawkings, M. S. Dixit, I. P. Duerdoth, W. G. Scott, Sherry Towers, I. Nakamura, C. Markus, Frans Meijers, T. Kawamoto, Claudio Grandi, S. Braibant, P. Utzat, P. Routenburg, Matthias Schröder, E. H. Vokurka, P. E.L. Clarke, J. Grunhaus, Allen Mincer, M. K. Jones, Erez Etzion, Stefan Kluth, Shlomit Tarem, Takehiko Mori, P. Mättig, J. P. Martin, G. A. Snow, C. P. Ward, A. Joly, V. Zacek, D. Glenzinski, Dezso Horvath, M. J. Losty, S. Robertson, Julie Kirk, M. Thiergen, Gregor Herten, Jean-Arcady Meyer, Ikuo Ueda, D. M. Strom, S. Orito, J. Bechtluft, Raimund Ströhmer, Daniele Bonacorsi, R. L. Coxe, S. De Jong, P. G. Estabrooks, R. K. Keeler, N. K. Watson, P. M. Watkins, S. D. Talbot, F. G. Oakham, B. Schmitt, O. C. Cooke, Claire Shepherd-Themistocleous, P. Pfeifenschneider, M. Kolrep, E. L. Barberio, J. A. McKenna, J. E. Pilcher, S. Söldner-Rembold, P. Hüntemeyer, C. Sbarra, D. Eatough, Sachio Komamiya, C. Dallapiccola, P. Poffenberger, Theodoros Geralis, A. T. Watson, Randall Sobie, G. D. Lafferty, J. Patt, André Schöning, J. von Krogh, A. A. Faust, S. A. Robins, O. Sahr, N. Altekamp, H. Voss, T. P. Kokott, M. Gruwé, R. J. Barlow, T. Saeki, D. J. Miller, R. Bartoldus, A. J. Martin, R. Davis, L. A. del Pozo, B. Stockhausen, Paul Kyberd, F. K. Loebinger, Alessandra Fanfani, K. Ackerstaff, P. Scharff-Hansen, T. J. McMahon, Beatrix Dienes, I. J. Bloodworth, A. Hocker, H. O. Ogren, J. Steuerer, C. Couyoumtzelis, Ivor Fleck, Silvia Arcelli, M. Schumacher, E. Lefebvre, S. M. Gascon-Shotkin, R. K. Carnegie, Guenter Duckeck, Satoshi Mihara, Joleen Pater, M. Herndon, Christoph Geich-Gimbel, A. Klier, M. Bobinski, J. A. Wilson, C. K. Hargrove, R. Giacomelli, A. Oh, F. Odorici, M. Fierro, P. Gagnon, S. Baumann, Ekg Sarkisyan, Yoram Rozen, S. B. Anderson, M. Foucher, D. Chrisman, G. D. Long, D. Lazic, Matthew Evans, A. M. Rossi, John Allison, P. Szymanski, E. A. Mckigney, P. W. Jeffreys, W. P. Lai, Vakhtang Kartvelishvili, K. Stephens, Junichi Kanzaki, R. G. Kellogg, J. E. Conboy, A. Fürtjes, Csaba Hajdu, D. Karlen, A. Sittler, Stefano Marcellini, J. Goldberg, J. M. Roney, Stan Bentvelsen, Lutz Feld, N. I. Geddes, Peter Schleper, Michael Hildreth, V. Gibson, N. L. Rodning, Zoltan Laszlo Trocsanyi, B. Poli, D. I. Futyan, B. Nellen, Volker Blobel, T. R. Junk, P. Vikas, D. Lanske, I. Trigger, D. R. Ward, T. Kress, A. M. Smith, S. D. Bird, D. Axen, A. Jawahery, H. G. Evans, Peter Sherwood, M. J. Goodrick, I. Cohen, Christoph Rembser, Alexander Wagner, J. Ludwig, K. Runge, P. Bock, Stephen Lloyd, James Pinfold, R. Perez-Ochoa, D. G. Fong, J. Gascon, Ehud Duchovni, M. Jimack, J. W. Gary, D. S. Koetke, A. Michelini, Marcello Mannelli, K. Stoll, Andris Skuja, T. Kobayashi, S. Petzold, Tetsuro Mashimo, W. Gorn, R. Kowalewski, R. Van Kooten, Gideon Alexander, Paolo Capiluppi, F. Wäckerle, D. M. Gingrich, M. Fanti, W. R. Gibson, Robert McPherson, Mathieu Doucet, R. M. Brown, Lorne Levinson, A. Skillman, R. D. Heuer, Reda Tafirout, Klaus Kurt Desch, Fabrizio Fabbri, E. Torrence, K. Nagai, D. R. Rust, A. M. Lee, E. von Törne, F. Scharf, German Martinez, M. A. Thomson, E. K. U. Gross, M. Sproston, J. Schieck, W. Mohr, and A. Posthaus
Subjects: Physics, Particle physics, Physics and Astronomy (miscellaneous), Meson, Hadron, Fragmentation function, High Energy Physics::Experiment, Channel analysis, Scalar meson, Engineering (miscellaneous)
Abstract: Inclusive production of the ${\rm f_0}(980)$, ${\rm f}_2(1270)$ and $\phi(1020)$ resonances has been studied in a sample of 4.3 million hadronic ${\rm Z}^0$ decays from the OPAL experiment at LEP. A coupled channel analysis has been used for the ${\rm f}_0$ in simultaneous fits to the resonances in inclusive $\pi^+\pi^-$ and ${\rm K^+K^-}$ mass spectra. Fragmentation functions are reported for the three states. Total inclusive rates are measured to be $0.141 \pm 0.007 \pm 0.011$${\rm f}_0$, $0.155\pm0.011\pm0.018$${\rm f}_2$ and $0.091\pm0.002\pm0.003$$\phi$ mesons per hadronic ${\rm Z}^0$ decay. The production properties of the ${\rm f}_0$, including those in three-jet events, are compared with those of the ${\rm f}_2$ and $\phi$, and with the Lund string model of hadron production. All measurements are consistent with the hypothesis that the ${\rm f_0}(980)$ is a conventional ${\rm q\bar q}$ scalar meson.
Published: 1998

49. Search for anomalous production of photonic events with missing energy in ${\rm e^+e^-}$ collisions at $\sqrt{s} = 130$ –172 GeV

Author: A. Klier, P. Routenburg, C. Dallapiccola, M. Hauschild, C. Markopoulos, C. Markus, G. T. Jones, E. H. Vokurka, N. Altekamp, H. Voss, S. Orito, W. Gorn, S. R. Lautenschlager, H. A. Neal, R. J. Barlow, D. J. Miller, Stefan Kluth, E. K.G. Sarkisyan, U. Ruppel, M. R. Ingram, J. Lauber, S. Betts, M. Hapke, W. J. McDonald, A. Sittler, P. G. Estabrooks, O. Runolfsson, G. W. Wilson, V. Zacek, D. E. Hutchcroft, N. J. Oldershaw, Gideon Bella, R. Howard, U. Jost, N. K. Watson, S. D. Talbot, G. Yekutieli, P. Scharff-Hansen, A. D. Schaile, H. J. Burckhart, Jacqueline Batley, C. Beeston, M. J. Oreglia, W. M. Sang, Gregor Herten, B. Wilkens, A. Biguzzi, Raimund Ströhmer, N. Rodning, P. M. Watkins, A. Rooke, J. E. Pilcher, Gabriella Pasztor, Claudio Grandi, J. Grunhaus, D. C. Imrie, P. R. Hobson, J. G. Layter, I. Nakamura, A. K. Honma, R. Van Kooten, F. G. Oakham, D. Eatough, B. Schmitt, E. L. Barberio, R. Bartoldus, D. Lui, B. Nellen, A. M. Smith, A. Oh, Paolo Capiluppi, J-P. Meyer, John Allison, Richard Keeler, R. J. Hemingway, H. O. Ogren, L. Levinson, G. D. Long, M. Schumacher, K. Stephens, G. A. Snow, C. P. Ward, E. Lefebvre, R. L. Coxe, Christoph Geich-Gimbel, J. R. Carter, Georges Azuelos, C. R. Jones, G. Mikenberg, T. Kawamoto, Stefan Schmitt, A. Macpherson, B. W. Kennedy, P. Jovanovic, R. Lahmann, Austin Ball, S. Söldner-Rembold, F. Odorici, A. Hocker, G. N. Patrick, Peter Krieger, R. G. Kellogg, P. E.L. Clarke, Alessandro Montanari, R. Davis, Silvia Arcelli, Hans-Christian Schultz-Coulon, Csaba Hajdu, D. Chrisman, R. Perez-Ochoa, G. D. Lafferty, M. Verzocchi, K. W. Bell, Otmar Biebel, H. G. Evans, M. J. Goodrick, P. Igo-Kemenes, N. I. Geddes, Michael Hildreth, P. Gagnon, M. K. Jones, J. P. Martin, J. Letts, Christoph Rembser, E. Tsur, S. Komamiya, V. Gibson, J. S. White, Stefano Marcellini, C. Hartmann, D. G. Fong, J. Gascon, D. E. Plane, S. Dado, J. Pinfold, J. C. Hill, D. Lazic, T. J. McMahon, C. Couyoumtzelis, P. Mättig, S. Asai, Vakhtang Kartvelishvili, G. P. Siroli, S. De Jong, Christoph Schwick, K. Ackerstaff, F. Fiedler, F. Wäckerle, L. Brigliadori, S. Baumann, H. Jeremie, Stephen Lloyd, Stephen Hillier, R. K. Carnegie, E. Gross, Dave Charlton, B. Poli, F. Scharf, German Martinez, I. J. Bloodworth, Peter Schleper, K. Kawagoe, J. E. Conboy, A. Fürtjes, K. Sachs, J. Goldberg, E. A. Mckigney, S. Tarem, B. C. Shen, G. M. Dallavalle, T. R. Junk, J. M. Roney, M. Fierro, J. E.G. Edwards, R. Bürgin, H. M. Fischer, A. N. Bell, D. M. Gingrich, M. Herndon, B. Dienes, I. Trigger, A. Joly, J. W. Gary, W. P. Lai, D. S. Koetke, Marcello Mannelli, Guenter Duckeck, Lutz Feld, R. Mir, M. Bobinski, Norbert Wermes, Sherry Towers, Paolo Giacomelli, J. A. Wilson, M. Hansroul, D. R. Ward, M. Jimack, Siegfried Bethke, T. Kress, W. G. Scott, A. Michelini, H. Mes, O. Schaile, P. W. Jeffreys, M. Foucher, I. P. Duerdoth, S. D. Bird, G. G. Hanson, A. M. Lee, G. Alexander, M. Boutemeur, F. S. Merritt, Richard Teuscher, S. Braibant, S. Yamashita, R. Rylko, B. Stockhausen, Paul Kyberd, F. K. Loebinger, D. I. Futyan, A. S. Turcot, C. Burgard, I. Cohen, Ivor Fleck, G. Giacomelli, S. W. O'Neale, A. Jawahery, Joleen Pater, M. F. Turner-Watson, R. W. Springer, R. J. Homer, D. Karlen, T. Saeki, P. I. Kayal, S. F. Ashby, R. Giacomelli, Sven Menke, Daniele Bonacorsi, Z. Trácsanyi, Peter Sherwood, S. Mihara, S. M. Gascon-Shotkin, M. A. Thomson, S. Robertson, D. Glenzinski, Dezso Horvath, M. J. Losty, R. Sobie, M. S. Dixit, Frans Meijers, P. S. Wells, J. Bechtluft, K. J. Anderson, M. Fanti, D. Zer-Zion, V. Blobel, J. A. McKenna, J. Ludwig, Reda Tafirout, Klaus Kurt Desch, S. A. Robins, R. Hawkings, K. Runge, P. Bock, E. Torrence, S. Petzold, Matthew Evans, A. M. Rossi, M. Kolrep, M. Sproston, Terry Richard Wyatt, C. Y. Chang, P. Vikas, D. Lanske, T. Mori, J. von Krogh, D. Lellouch, W. R. Gibson, J. E. Bloomer, D. Axen, K. R. Hossain, S. B. Anderson, J. Pálinkás, J. Kirk, P. Szymanski, P. Taras, Michael Kobel, R. M. Brown, E. von Tärne, Theodoros Geralis, A. Skillman, O. C. Cooke, P. Pfeifenschneider, A. T. Watson, L. A. del Pozo, Stan Bentvelsen, Allen Mincer, T. P. Kokott, T. Mashimo, Alessandra Fanfani, J. Patt, André Schöning, Robert McPherson, C. Sbarra, P. Huntemeyer, A. A. Carter, Ron Folman, T. Kobayashi, Mathieu Doucet, R. D. Heuer, P. Utzat, A. A. Faust, Fabrizio Fabbri, J. Schieck, D. M. Strom, E. Duchovni, W. Mohr, A. Posthaus, K. Nagai, D. R. Rust, J. Kanzaki, S. Tanaka, Tara Shears, P. A. Hart, P. Poffenberger, K. Ishii, Claire Shepherd-Themistocleous, A. Wagner, Matthias Schröder, T. Behnke, J. Steuerer, M. Thiergen, A. Macchiolo, M. Gruwé, C. M. Hawkes, Richard Nisius, Marco Cuffiani, U. Müller, A. J. Martin, C. K. Hargrove, K. Stoll, Andris Skuja, and Y. Rozen
Subjects: Physics, Particle physics, Missing energy, Physics and Astronomy (miscellaneous), Electron–positron annihilation, Physics beyond the Standard Model, Standard Model, Nuclear physics, Pair production, Neutralino, High Energy Physics::Experiment, Production (computer science), Engineering (miscellaneous), Energy (signal processing)
Abstract: Photonic events with large missing energy have been observed in $\mathrm{e^+e^-}$ collisions at centre-of-mass energies of 130, 136, 161 and 172 GeV using the OPAL detector at LEP. Results are presented based on search topologies designed to select events with a single photon and missing transverse energy or events with a pair of acoplanar photons. In both search topologies, cross-section measurements are performed within the kinematic acceptance of the selection. These results are compared with the expectations from the Standard Model processes ${\rm e^+e^-}\to \nu\overline\nu \gamma (\gamma )$ (single-photon) and ${\rm e^+e^-}\to \nu\overline\nu \gamma \gamma (\gamma )$ (acoplanar-photons). No evidence is observed for new physics contributions to these final states. Upper limits on $\sigma({\rm e^+e^- \to XY)\cdot BR(X\to Y\gamma })$ and $\sigma({\rm e^+e^- \to XX)\cdot BR^2(X\to Y\gamma })$ are derived for the case of stable and invisible Y. These limits apply to single and pair production of excited neutrinos (${\rm X}= \nu^*,{\rm Y}= \nu$), to neutralino production (${\rm X}=\tilde\chi^0_2, {\rm Y}=\tilde\chi^0_1$), and to supersymmetric models in which ${\rm X}= \tilde\chi^0_1$ and ${\rm Y}=\tilde{\rm G}$ is a light gravitino. For the latter scenario, the results of the acoplanar-photons search are used to provide mode l-dependent lower limits on the mass of the lightest neutralino.
Published: 1998

50. Measurements of the Bs0 and Λb0 lifetimes

Author: K Ackerstaff, G Alexander, J Allison, N Altekamp, K.J Anderson, S Anderson, S Arcelli, S Asai, S.F Ashby, D Axen, G Azuelos, A.H Ball, E Barberio, R.J Barlow, R Bartoldus, J.R Batley, S Baumann, J Bechtluft, C Beeston, T Behnke, A.N Bell, K.W Bell, G Bella, S Bentvelsen, S Bethke, S Betts, O Biebel, A Biguzzi, S.D Bird, V Blobel, I.J Bloodworth, J.E Bloomer, M Bobinski, P Bock, D Bonacorsi, M Boutemeur, S Braibant, L Brigliadori, R.M Brown, H.J Burckhart, C Burgard, R Bürgin, P Capiluppi, R.K Carnegie, A.A Carter, J.R Carter, C.Y Chang, D.G Charlton, D Chrisman, P.E.L Clarke, I Cohen, J.E Conboy, O.C Cooke, C Couyoumtzelis, R.L Coxe, M Cuffiani, S Dado, C Dallapiccola, G.M Dallavalle, R Davis, S De Jong, L.A del Pozo, K Desch, B Dienes, M.S Dixit, M Doucet, E Duchovni, G Duckeck, I.P Duerdoth, D Eatough, J.E.G Edwards, P.G Estabrooks, H.G Evans, M Evans, F Fabbri, A Fanfani, M Fanti, A.A Faust, L Feld, F Fiedler, M Fierro, H.M Fischer, I Fleck, R Folman, D.G Fong, M Foucher, A Fürtjes, D.I Futyan, P Gagnon, J.W Gary, J Gascon, S.M Gascon-Shotkin, N.I Geddes, C Geich-Gimbel, T Geralis, G Giacomelli, P Giacomelli, R Giacomelli, V Gibson, W.R Gibson, D.M Gingrich, D Glenzinski, J Goldberg, M.J Goodrick, W Gorn, C Grandi, E Gross, J Grunhaus, M Gruwé, C Hajdu, G.G Hanson, M Hansroul, M Hapke, C.K Hargrove, P.A Hart, C Hartmann, M Hauschild, C.M Hawkes, R Hawkings, R.J Hemingway, M Herndon, G Herten, R.D Heuer, M.D Hildreth, J.C Hill, S.J Hillier, P.R Hobson, A Hocker, R.J Homer, A.K Honma, D Horváth, K.R Hossain, R Howard, P Hüntemeyer, D.E Hutchcroft, P Igo-Kemenes, D.C Imrie, M.R Ingram, K Ishii, A Jawahery, P.W Jeffreys, H Jeremie, M Jimack, A Joly, C.R Jones, G Jones, M Jones, U Jost, P Jovanovic, T.R Junk, J Kanzaki, D Karlen, V Kartvelishvili, K Kawagoe, T Kawamoto, P.I Kayal, R.K Keeler, R.G Kellogg, B.W Kennedy, J Kirk, A Klier, S Kluth, T Kobayashi, M Kobel, D.S Koetke, T.P Kokott, M Kolrep, S Komamiya, T Kress, P Krieger, J von Krogh, P Kyberd, G.D Lafferty, R Lahmann, W.P Lai, D Lanske, J Lauber, S.R Lautenschlager, J.G Layter, D Lazic, A.M Lee, E Lefebvre, D Lellouch, J Letts, L Levinson, S.L Lloyd, F.K Loebinger, G.D Long, M.J Losty, J Ludwig, D Lui, A Macchiolo, A Macpherson, M Mannelli, S Marcellini, C Markopoulos, C Markus, A.J Martin, J.P Martin, G Martinez, T Mashimo, P Mättig, W.J McDonald, J McKenna, E.A Mckigney, T.J McMahon, R.A McPherson, F Meijers, S Menke, F.S Merritt, H Mes, J Meyer, A Michelini, G Mikenberg, D.J Miller, A Mincer, R Mir, W Mohr, A Montanari, T Mori, U Müller, S Mihara, K Nagai, I Nakamura, H.A Neal, B Nellen, R Nisius, S.W O'Neale, F.G Oakham, F Odorici, H.O Ogren, A Oh, N.J Oldershaw, M.J Oreglia, S Orito, J Pálinkás, G Pásztor, J.R Pater, G.N Patrick, J Patt, R Perez-Ochoa, S Petzold, P Pfeifenschneider, J.E Pilcher, J Pinfold, D.E Plane, P Poffenberger, B Poli, A Posthaus, C Rembser, S Robertson, S.A Robins, N Rodning, J.M Roney, A Rooke, A.M Rossi, P Routenburg, Y Rozen, K Runge, O Runolfsson, U Ruppel, D.R Rust, R Rylko, K Sachs, T Saeki, W.M Sang, E.K.G Sarkisyan, C Sbarra, A.D Schaile, O Schaile, F Scharf, P Scharff-Hansen, J Schieck, P Schleper, B Schmitt, S Schmitt, A Schöning, M Schröder, H.C Schultz-Coulon, M Schumacher, C Schwick, W.G Scott, T.G Shears, B.C Shen, C.H Shepherd-Themistocleous, P Sherwood, G.P Siroli, A Sittler, A Skillman, A Skuja, A.M Smith, G.A Snow, R Sobie, S Söldner-Rembold, R.W Springer, M Sproston, K Stephens, J Steuerer, B Stockhausen, K Stoll, D Strom, R Ströhmer, P Szymanski, R Tafirout, S.D Talbot, S Tanaka, P Taras, S Tarem, R Teuscher, M Thiergen, M.A Thomson, E von Törne, E Torrence, S Towers, I Trigger, Z Trócsányi, E Tsur, A.S Turcot, M.F Turner-Watson, P Utzat, R Van Kooten, M Verzocchi, P Vikas, E.H Vokurka, H Voss, F Wäckerle, A Wagner, C.P Ward, D.R Ward, P.M Watkins, A.T Watson, N.K Watson, P.S Wells, N Wermes, J.S White, B Wilkens, G.W Wilson, J.A Wilson, T.R Wyatt, S Yamashita, G Yekutieli, V Zacek, and D Zer-Zion
Subjects: Baryon, Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, 0103 physical sciences, Hadron, High Energy Physics::Experiment, 010306 general physics, Lambda, 01 natural sciences, Bar (unit)
Abstract: This paper presents updated measurements of the lifetimes of the B^0_s meson and the \Lambda_b baryon using 4.4 million hadronic Z^0 decays recorded by the OPAL detector at LEP from 1990 to 1995. A sample of B^0_s decays is obtained using D_s^- \ell^+ combinations, where the D_s^- is fully reconstructed in the \phi \pi^-, K^*0 K^- and K^- K^0_S decay channels and partially reconstructed in the \phi \ell^- \nu(bar) X decay mode. A sample of \Lambda_b decays is obtained using \Lambda_c^+ \ell^- combinations, where the \Lambda_c^+ is fully reconstructed in its decay to a p K^- \pi^+ final state and partially reconstructed in the \Lambda \ell^+ \nu X decay channel. From 172 +/- 28 D_s^- \ell^+ combinations attributed to B^0_s decays, the measured lifetime is \tau(B^0_s) = 1.50 +0.16 -0.15 +/- 0.04 ps, where the errors are statistical and systematic, respectively. From the 129 +\- 25 \Lamda_c^+ \ell^- combinations attributed to \Lambda_b decays, the measured lifetime \tau(\Lambda_b) = 1.29 +0.24 -0.22 +/- 0.06 ps, where the errors are statistical and systematic, respectively.
Published: 1998

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