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610 results on '"E. J. Stephenson"'

1. Spin decoherence and off-resonance behavior of radio-frequency-driven spin rotations in storage rings

Author

N. N. Nikolaev, F. Rathmann, J. Slim, A. Andres, V. Hejny, A. Nass, A. Kacharava, P. Lenisa, J. Pretz, A. Saleev, V. Shmakova, H. Soltner, F. Abusaif, A. Aggarwal, A. Aksentev, B. Alberdi, L. Barion, I. Bekman, M. Beyß, C. Böhme, B. Breitkreutz, N. Canale, G. Ciullo, S. Dymov, N.-O. Fröhlich, R. Gebel, M. Gaisser, K. Grigoryev, D. Grzonka, J. Hetzel, O. Javakhishvili, V. Kamerdzhiev, S. Karanth, I. Keshelashvili, A. Kononov, K. Laihem, A. Lehrach, N. Lomidze, B. Lorentz, G. Macharashvili, A. Magiera, D. Mchedlishvili, A. Melnikov, F. Müller, A. Pesce, V. Poncza, D. Prasuhn, D. Shergelashvili, N. Shurkhno, S. Siddique, A. Silenko, S. Stassen, E. J. Stephenson, H. Ströher, M. Tabidze, G. Tagliente, Y. Valdau, M. Vitz, T. Wagner, A. Wirzba, A. Wrońska, P. Wüstner, and M. Żurek

Subjects
Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

High-frequency driven resonant spin rotators are routinely used as standard instruments in polarization experiments in particle and nuclear physics. Maintaining the continuous exact parametric spin resonance condition of the equality of the spin rotator and the spin precession frequency during operation is one of the challenges. We present a detailed analytical description of the effects of detuning the exact spin resonance on the precessing vertical and in-plane components of the polarization. An important part of the formalism presented here is the consideration of experimentally relevant spin decoherence effects. Within the developed formalism, we address the impact of feedback via pilot-bunch-based comagnetometry on continuous spin flips and on the related interpretation of charged-particle electric dipole moment searches using storage rings. We propose a spin-flip-based tomography of the longitudinal profile of polarization in a bunch, which is important for the evaluation of the polarization-dependent luminosity in collider experiments. We emphasize the potential importance of the previously unexplored phase of the horizontal polarization of the envelope as an indicator of the stability of radio-frequency-driven spin rotations in storage rings and as a testing ground for spin decoherence mechanisms.

Published
2024
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2. First Search for Axionlike Particles in a Storage Ring Using a Polarized Deuteron Beam

Author

S. Karanth, E. J. Stephenson, S. P. Chang, V. Hejny, S. Park, J. Pretz, Y. K. Semertzidis, A. Wirzba, A. Wrońska, F. Abusaif, A. Aggarwal, A. Aksentev, B. Alberdi, A. Andres, L. Barion, I. Bekman, M. Beyß, C. Böhme, B. Breitkreutz, C. von Byern, N. Canale, G. Ciullo, S. Dymov, N.-O. Fröhlich, R. Gebel, K. Grigoryev, D. Grzonka, J. Hetzel, O. Javakhishvili, H. Jeong, A. Kacharava, V. Kamerdzhiev, I. Keshelashvili, A. Kononov, K. Laihem, A. Lehrach, P. Lenisa, N. Lomidze, B. Lorentz, A. Magiera, D. Mchedlishvili, F. Müller, A. Nass, N. N. Nikolaev, A. Pesce, V. Poncza, D. Prasuhn, F. Rathmann, A. Saleev, D. Shergelashvili, V. Shmakova, N. Shurkhno, S. Siddique, J. Slim, H. Soltner, R. Stassen, H. Ströher, M. Tabidze, G. Tagliente, Y. Valdau, M. Vitz, T. Wagner, and P. Wüstner

Subjects
Physics, QC1-999
Abstract

Based on the notion that the local dark-matter field of axions or axionlike particles (ALPs) in our Galaxy induces oscillating couplings to the spins of nucleons and nuclei (via the electric dipole moment of the latter and/or the paramagnetic axion-wind effect), we establish the feasibility of a new method to search for ALPs in storage rings. Based on previous work that allows us to maintain the in-plane polarization of a stored deuteron beam for a few hundred seconds, we perform a first proof-of-principle experiment at the Cooler Synchrotron (COSY) to scan momenta near 970 MeV/c. This entails a scan of the spin-precession frequency. At resonance between the spin-precession frequency of deuterons and the ALP-induced electric dipole moment (EDM) oscillation frequency, there is an accumulation of the polarization component out of the ring plane. Since the axion frequency is unknown, the momentum of the beam and, consequently, the spin-precession frequency are ramped to search for a vertical polarization change that occurs when the resonance is crossed. At COSY, four beam bunches with different polarization directions are used to make sure that no resonance is missed because of the unknown relative phase between the polarization precession and the axion or ALP field. A frequency window of 1.5 kHz width around the spin-precession frequency of 121 kHz is scanned. We describe the experimental procedure and a test of the methodology with the help of a radio-frequency Wien filter located on the COSY ring. No ALP resonance is observed. As a consequence, an upper limit of the oscillating EDM component of the deuteron as well as its axion coupling constants are provided.

Published
2023
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3. Connection between zero chromaticity and long in-plane polarization lifetime in a magnetic storage ring

Author

G. Guidoboni, E. J. Stephenson, A. Wrońska, Z. Bagdasarian, J. Bsaisou, S. Chekmenev, G. Ciullo, S. Dymov, D. Eversmann, M. Gaisser, R. Gebel, V. Hejny, N. Hempelmann, F. Hinder, A. Kacharava, I. Keshelashvili, P. Kulessa, P. Lenisa, A. Lehrach, B. Lorentz, P. Maanen, R. Maier, D. Mchedlishvili, S. Mey, A. Nass, A. Pesce, Y. Orlov, J. Pretz, D. Prasuhn, F. Rathmann, M. Rosenthal, A. Saleev, Y. K. Semertzidis, Y. Senichev, V. Shmakova, H. Stockhorst, H. Ströher, R. Talman, P. Thörngren Engblom, F. Trinkel, Yu. Valdau, C. Weidemann, P. Wüstner, M. Żurek, and D. Zyuzin

Subjects
Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

In this paper, we demonstrate the connection between a magnetic storage ring with additional sextupole fields set so that the x and y chromaticities vanish and the maximizing of the lifetime of in-plane polarization (IPP) for a 0.97-GeV/c deuteron beam. The IPP magnitude was measured by continuously monitoring the down-up scattering asymmetry (sensitive to sideways polarization) in an in-beam, carbon-target polarimeter and unfolding the precession of the IPP due to the magnetic anomaly of the deuteron. The optimum operating conditions for a long IPP lifetime were made by scanning the field of the storage ring sextupole magnet families while observing the rate of IPP loss during storage of the beam. The beam was bunched and electron cooled. The IPP losses appear to arise from the change of the orbit circumference, and consequently the particle speed and spin tune, due to the transverse betatron oscillations of individual particles in the beam. The effects of these changes are canceled by an appropriate sextupole field setting.

Published
2018
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4. Erratum: Azimuthal Anisotropy of KS0 and Λ+Λ¯ Production at Midrapidity from Au+Au Collisions at sNN=130 GeV [Phys. Rev. Lett. 89 , 132301 (2002)]

Author

S. P. Chernenko, W. J. Llope, A. Cardenas, H. Long, R. Lednický, V. A. Nikitin, K. E. Shestermanov, A. Stolpovsky, R. S. Longacre, W. Christie, L. Kotchenda, H. Bichsel, P. Seyboth, V. Trofimov, Guy Paic, A. Chikanian, A. V. Brandin, S. S. Shimanskii, A. I. Kulikov, Masashi Kaneta, W. M. Zhang, L. C. Bland, Y. Panebratsev, R.Kh. Kutuev, Andrey Vasiliev, Joram Berger, T. Todoroki, Adam Ryszard Kisiel, J. B. Carroll, A. E. Yakutin, G. Igo, M. Oldenburg, H. J. Crawford, M. Castro, M. Calderon De La Barca Sanchez, G. Rai, J. W. Mitchell, N. Schmitz, Janet Elizabeth Seger, VL Rykov, B. D. Anderson, V. Petrov, E. Shahaliev, A. Boucham, T. J. Humanic, V. B. Dunin, A. C. Saulys, Z. Z. Xu, Q. Li, R. Witt, S. E. Vigdor, T. W. Henry, Christian Claude Kuhn, W. S. Deng, V. Ghazikhanian, Nikita Smirnov, I.A. Savin, M. Csanád, A. I. Pavlinov, F. Liu, M. B. Tonjes, J. W. Harris, B. E. Bonner, N. T. Porile, O. D. Tsai, J. L. Romero, Mirko Planinic, H. M. Spinka, C. E. Allgower, G. Eppley, S. Bekele, V. Morozov, Michael Kramer, M. Cherney, B. Lasiuk, E. Finch, Thomas Michael Cormier, R. Willson, D. G. Underwood, Michael W. Anderson, E. Gushin, P. Yepes, V. Eckardt, R. Ma, P. Nevski, J. H. Thomas, D. Hardtke, F. Laue, A. H. Tang, R. D. Majka, J. Pluta, L. Liu, V. M. Leontiev, Olivier Ravel, G. LoCurto, C. O. Blyth, E. Hjort, I. Zborovský, Yu A. Matulenko, M. Horsley, G. Skoro, B. Stringfellow, T. S. McShane, Rene Bellwied, C. P. Lansdell, R. E. Tribble, R.J.M. Snellings, Gerald W Hoffmann, J. N. Marx, B. Choi, J. G. Cramer, Thomas Dietel, Alexander Kovalenko, L. V. Nogach, A. P. Meschanin, Y. Fisyak, Ian Johnson, Christophe Pierre Suire, J. Sowinski, J. Schambach, D. Reichhold, T. J. M. Symons, T. Niida, A. Lebedev, M. M. de Moura, A. Szanto de Toledo, T. Pawlak, Morton Kaplan, P. Sorensen, G. Van Buren, Sevil Salur, Saurabh Pandey, A. Tai, T. W. Ludlam, J. Amonett, J. M. Nelson, V. Emelianov, D. Keane, W. Peryt, R. Stock, L. G. Efimov, D. Seliverstov, A. Schüttauf, G. S. Averichev, J. Porter, C. Roy, A. Klyachko, Vladimir Tikhomirov, P. Chaloupka, S. Trentalange, A. Ishihara, Yu Chen, Gregory Rakness, B. K. Srivastava, I. M. Vasilevski, F. Retiere, J. Gans, Boris Hippolyte, J. C. Dunlop, Zubayer Ahammed, M. J. LeVine, H. G. Ritter, A. S. Konstantinov, B. Norman, A. A. Kuznetsov, S. Y. Panitkin, E. Yamamoto, J. Engelage, David Lynn, J. G. Ma, J. Takahashi, M. A. C. Lamont, S. B. Nurushev, Z. Milosevich, N. G. Minaev, Sergey Voloshin, K. J. Foley, V. S. Shvetcov, Q. J. Liu, C. A. Whitten, J. Baudot, A. Rose, Y. V. Zanevski, S. Lange, S. J. Lindenbaum, Yu. Ivanshin, N. Xu, John N. Wood, M. Guedon, A. M. Poskanzer, A. M. VanderMolen, Russell Wells, J. M. Landgraf, M. Strikhanov, A. Billmeier, J. Putschke, J. W. Watson, A. Ogawa, Thomas A. Trainor, R. P. Scharenberg, Christina Markert, H. S. Matis, G. Odyniec, J. Sandweiss, Z. Liu, W. W. Jacobs, G. D. Westfall, H. Ward, L. S. Schroeder, S. V. Razin, L. Gaudichet, H. Zhang, Jay Roberts, Jinghui Yang, Malgorzata Anna Janik, C. L. Kunz, K. Krueger, C. F. Moore, C. Struck, M. Lopez-Noriega, I. Sakrejda, M. L. Miller, Fuqiang Wang, P. Szarwas, A. S. Hirsch, P. M. Jacobs, P. Kravtsov, C. Adler, E. G. Judd, Michael A. Thompson, Michal Sumbera, Jeffrey G. Reid, A. A. P. Suaide, E. Sugarbaker, S. R. Klein, V. Faine, J. Castillo, S. W. Wissink, J. E. Draper, H. Z. Huang, N.D. Gagunashvili, O. Barannikova, D. L. Olson, Sukalyan Chattopadhyay, T. J. Hallman, V. Perevoztchikov, K. Filimonov, A. A. Derevschikov, Marie Germain, V. I. Yurevich, A. N. Zubarev, M. Messer, P. Fachini, V. V. Belaga, Peter Graham Jones, Lee Stuart Barnby, F. Meissner, L. Didenko, M. Kopytine, J. Fu, M. Tokarev, K. Schweda, H. H. Wieman, J. Kiryluk, Rajarshi Ray, L. Lakehal-Ayat, W. A. Love, Vitaly Okorokov, Bernd Surrow, J. L. Klay, C. A. Gagliardi, A. Ridiger, T. Herston, R. V. Cadman, S. Heppelmann, D. Flierl, Frank Jm Geurts, L. Martin, J. P. Coffin, O. V. Rogachevski, V. A. Moiseenko, Marcelo Gameiro Munhoz, D. J. Prindle, E. J. Stephenson, M. A. Lisa, S. Margetis, O. A. Grachov, B. Erazmus, Gerd Joachim Kunde, D. Cebra, A. Bravar, Yu Melnick, J. Balewski, Claude Andre Pruneau, T. Ullrich, R. Zoulkarneev, V. Grigoriev, E. Potrebenikova, T. Ljubicic, and H. Caines

Subjects
Physics, Nuclear physics, Azimuth, General Physics and Astronomy, Anisotropy
Published
2021

5. Precision measurements of differential cross sections and analyzing powers in elastic deuteron-deuteron scattering at 65 MeV/nucleon

Author

Nasser Kalantar-Nayestanaki, M. Mahjour-Shafiei, E. J. Stephenson, St. Kistryn, H. Tavakoli-Zaniani, J. G. Messchendorp, R. Ramazani-Sharifabadi, A. Deltuva, Mohammad Eslami-Kalantari, A. Ramazani-Moghaddam-Arani, H. Mardanpour, E. Stephan, M. Mohammadi-Dadkan, A. Kozela, H. R. Amir-Ahmadi, C. D. Bailey, and Research unit Nuclear & Hadron Physics

Subjects
Physics, Elastic scattering, Nuclear and High Energy Physics, Scattering, Hadron, Nuclear Theory, nucleon, FOS: Physical sciences, Observable, four-nucleon system, elastic scattering, analyzing power, Nuclear physics, differential cross sections, Nuclear fusion, Nuclear Experiment (nucl-ex), Nucleon, Nuclear Experiment, Beam (structure), Spin-½
Abstract

We present measurements of differential cross sections and analyzing powers for the elastic 2H(~d; d)d scattering process. The data were obtained using a 130 MeV polarized deuteron beam. Cross sections and spin observables of the elastic scattering process were measured at the AGOR facility at KVI using two independent setups, namely BINA and BBS. The data harvest at setups are in excellent agreement with each other and allowed us to carry out a thorough systematic analysis to provide the most accurate data in elastic deuteron-deuteron scattering at intermediate energies. The results can be used to confront upcoming state-of-the-art calculations in the four-nucleon scattering domain, and will, thereby, provide further insights in the dynamics of three- and four-nucleon forces in few-nucleon systems., 10 pages, 7 figures

Published
2021

6. Influence of electron cooling on the polarization lifetime of a horizontally polarized storage ring beam

Author

Andreas Lehrach, G. Guidoboni, P. Lenisa, D. Prasuhn, V. Shmakova, I. Keshelashvili, Ralf Gebel, B. Lorentz, H. Ströher, A. Nass, Frank Rathmann, A.K. Kacharava, E. J. Stephenson, A. Pesce, D. Mchedlishvili, Yu. Valdau, J. Pretz, Richard Talman, Aleksandra Wrońska, A. Saleev, S. Dymov, Y. Senichev, C. Weidemann, S. Karanth, Nikolai N. Nikolaev, V. Hejny, G. Ciullo, and P. Wüstner

Subjects
Accelerator Physics (physics.acc-ph), Nuclear and High Energy Physics, Field (physics), Electron cooling, Socio-culturale, FOS: Physical sciences, Spin coherence time, 01 natural sciences, law.invention, PE2_2, Optics, PE2_1, law, Polarization, 0103 physical sciences, ddc:530, Polarization, Spin coherence time, Electron cooling, 010306 general physics, PE2_3, Instrumentation, Spin-½, Physics, 010308 nuclear & particles physics, business.industry, Polarization (waves), Deuterium, Physics::Accelerator Physics, Physics - Accelerator Physics, business, Intensity (heat transfer), Beam (structure), Storage ring
Abstract

A previous publication has shown that the in-plane polarization (IPP) component of a polarized 0.97-GeV/c deuteron beam in the COSY storage ring may acquire a polarization half-life in excess of 1000 s through a combination of beam bunching, electron cooling (prior to any spin manipulation), sextupole field adjustment, and a limitation of the beam intensity. This paper documents further tests pointing to additional gains in the IPP lifetime if cooling is active throughout the beam store., 11 pages, 6 figures Submitted to Physical Review Accelerators and Beams

Published
2020

7. Measurement of the neutron decay electron-antineutrino angular correlation by the aCORN experiment

Author

Gordon L. Jones, G. Darius, E. J. Stephenson, Maynard S. Dewey, M. P. Mendenhall, C. DeAngelis, Fred E. Wietfeldt, M. T. Hassan, B. Collett, G. Noid, Jeffrey S. Nico, Thomas R. Gentile, Fred B. Bateman, A. Komives, and W. A. Byron

Subjects
Physics, Coupling constant, Particle physics, Proton, media_common.quotation_subject, Nuclear Theory, Center (category theory), FOS: Physical sciences, Electron, Lambda, Asymmetry, High Energy Physics::Experiment, Neutron, Nuclear Experiment (nucl-ex), Nuclear Experiment, Electron neutrino, media_common
Abstract

The aCORN experiment measures the neutron decay electron-antineutrino correlation ($a$-coefficient) using a novel method based on an asymmetry in proton time-of-flight for events where the beta electron and recoil proton are detected in delayed coincidence. We report the data analysis and result from the second run at the NIST Center for Neutron Research, using the high-flux cold neutron beam on the new NG-C neutron guide end position: $a = -0.10758 \pm 0.00136 (\mbox{stat}) \pm 0.00148 (\mbox{sys})$. This is consistent within uncertainties with the result from the first aCORN run on the NG-6 cold neutron beam. Combining the two aCORN runs we obtain $a = -0.10782 \pm 0.00124 (\mbox{stat}) \pm 0.00133 (\mbox{sys})$, which has an overall relative standard uncertainty of 1.7 \%. The corresponding result for the ratio of weak coupling constants $\lambda = G_A/G_V$ is $\lambda = -1.2796\pm 0.0062$., Comment: 44 pages, 30 figures

Published
2020
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8. The aCORN Backscatter-Suppressed Beta Spectrometer

Author

B. Collett, A. Laptev, Gordon L. Jones, M. T. Hassan, Jeffrey S. Nico, G. Darius, Maynard S. Dewey, Fred B. Bateman, C. Trull, G. Noid, I. Stern, Fred E. Wietfeldt, A. Komives, E. J. Stephenson, M. P. Mendenhall, and C. DeAngelis

Subjects
Nuclear and High Energy Physics, Physics - Instrumentation and Detectors, Backscatter, Physics::Instrumentation and Detectors, FOS: Physical sciences, Electron, Scintillator, 01 natural sciences, Article, Nuclear physics, Optics, 0103 physical sciences, Neutron, 010306 general physics, Nuclear Experiment, Instrumentation, Physics, Spectrometer, 010308 nuclear & particles physics, business.industry, Detector, Instrumentation and Detectors (physics.ins-det), Beta (plasma physics), Scintillation counter, High Energy Physics::Experiment, business
Abstract

Backscatter of electrons from a beta spectrometer, with incomplete energy deposition, can lead to undesirable effects in many types of experiments. We present and discuss the design and operation of a backscatter-suppressed beta spectrometer that was developed as part of a program to measure the electron-antineutrino correlation coefficient in neutron beta decay (aCORN). An array of backscatter veto detectors surrounds a plastic scintillator beta energy detector. The spectrometer contains an axial magnetic field gradient, so electrons are efficiently admitted but have a low probability for escaping back through the entrance after backscattering. The design, construction, calibration, and performance of the spectrometer are discussed., 15 figures

Published
2019

10. aCORN: Measuring the electron-antineutrino correlation in neutron beta decay

Author

Maynard S. Dewey, W. A. Byron, A. Komives, Fred E. Wietfeldt, G. Darius, Gordon L. Jones, M. T. Hassan, M. P. Mendenhall, E. J. Stephenson, C. DeAngelis, Jeffrey S. Nico, and B. Collett

Subjects
Physics, QC1-999, Acorn, 01 natural sciences, Beta decay, 010305 fluids & plasmas, Nuclear physics, 0103 physical sciences, Neutron, High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment, Electron neutrino
Abstract

The aCORN experiment uses a novel asymmetry method to measure the electron-antineutrino correlation (a-coefficient) in free neutron decay that does not require precision proton spectroscopy. aCORN completed two physics runs at the NIST Center for Neutron Research. The first run on the NG-6 beam line obtained the result a = 0.1090 +/- 0.0030 (stat) +/- 0.0028 (sys), the most precise to date. The second run on the new NG-C high flux beam line promises an improvement in precision to ¡ 2%. In addition we show that an improved measurement of the neutrino asymmetry (B-coefficient) can be made using the aCORN apparatus on a highly polarized neutron beam.

Published
2019

11. Measuring the polarization of a rapidly precessing deuteron beam

Author

Z. Bagdasarian, S. Bertelli, D. Chiladze, G. Ciullo, J. Dietrich, S. Dymov, D. Eversmann, G. Fanourakis, M. Gaisser, R. Gebel, B. Gou, G. Guidoboni, V. Hejny, A. Kacharava, V. Kamerdzhiev, A. Lehrach, P. Lenisa, B. Lorentz, L. Magallanes, R. Maier, D. Mchedlishvili, W. M. Morse, A. Nass, D. Oellers, A. Pesce, D. Prasuhn, J. Pretz, F. Rathmann, V. Shmakova, Y. K. Semertzidis, E. J. Stephenson, H. Stockhorst, H. Ströher, R. Talman, P. Thörngren Engblom, Yu. Valdau, C. Weidemann, and P. Wüstner

Subjects
Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

This paper describes a time-marking system that enables a measurement of the in-plane (horizontal) polarization of a 0.97-GeV/c deuteron beam circulating in the Cooler Synchrotron (COSY) at the Forschungszentrum Jülich. The clock time of each polarimeter event is used to unfold the 120-kHz spin precession and assign events to bins according to the direction of the horizontal polarization. After accumulation for one or more seconds, the down-up scattering asymmetry can be calculated for each direction and matched to a sinusoidal function whose magnitude is proportional to the horizontal polarization. This requires prior knowledge of the spin tune or polarization precession rate. An initial estimate is refined by resorting the events as the spin tune is adjusted across a narrow range and searching for the maximum polarization magnitude. The result is biased toward polarization values that are too large, in part because of statistical fluctuations but also because sinusoidal fits to even random data will produce sizable magnitudes when the phase is left free to vary. An analysis procedure is described that matches the time dependence of the horizontal polarization to templates based on emittance-driven polarization loss while correcting for the positive bias. This information will be used to study ways to extend the horizontal polarization lifetime by correcting spin tune spread using ring sextupole fields and thereby to support the feasibility of searching for an intrinsic electric dipole moment using polarized beams in a storage ring. This paper is a combined effort of the Storage Ring EDM collaboration and the JEDI collaboration.

Published
2014
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12. Erratum: Synchrotron oscillation effects on an rf-solenoid spin resonance [Phys. Rev. ST Accel. Beams 15, 124202 (2012)]

Author

P. Benati, D. Chiladze, J. Dietrich, M. Gaisser, R. Gebel, G. Guidoboni, V. Hejny, A. Kacharava, V. Kamerdzhiev, P. Kulessa, A. Lehrach, P. Lenisa, B. Lorentz, R. Maier, D. Mchedlishvili, W. M. Morse, D. Öllers, A. Pesce, A. Polyanskiy, D. Prasuhn, F. Rathmann, Y. K. Semertzidis, E. J. Stephenson, H. Stockhorst, H. Ströher, R. Talman, Yu. Valdau, Ch. Weidemann, and P. Wüstner

Subjects
Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Published
2013
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13. Synchrotron oscillation effects on an rf-solenoid spin resonance

Author

P. Benati, D. Chiladze, J. Dietrich, M. Gaisser, R. Gebel, G. Guidoboni, V. Hejny, A. Kacharava, V. Kamerdzhiev, P. Kulessa, A. Lehrach, P. Lenisa, B. Lorentz, R. Maier, D. Mchedlishvili, W. M. Morse, D. Öllers, A. Pesce, A. Polyanskiy, D. Prasuhn, F. Rathmann, Y. K. Semertzidis, E. J. Stephenson, H. Stockhorst, H. Ströher, R. Talman, Yu. Valdau, Ch. Weidemann, and P. Wüstner

Subjects
Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

New measurements are reported for the time dependence of the vertical polarization of a 0.97 GeV/c deuteron beam circulating in a storage ring and perturbed by an rf solenoid. The storage ring is the cooler synchrotron (COSY) located at the Forschungszentrum Jülich. The beam polarization was measured continuously using a 1.5 cm thick carbon target located at the edge of the circulating deuteron beam and the scintillators of the EDDA detector. An rf solenoid mounted on the ring was used to generate fields at and near the frequency of the 1-Gγ spin resonance. Measurements were made of the vertical beam polarization as a function of time with the operation of the rf solenoid in either fixed or continuously variable frequency mode. Using rf-solenoid strengths as large as 2.66×10^{-5} revolutions/turn, slow oscillations (∼1 Hz) were observed in the vertical beam polarization. When the circulating beam was continuously electron cooled, these oscillations completely reversed the polarization and showed no sign of diminishing in amplitude. But for the uncooled beam, the oscillation amplitude was damped to nearly zero within a few seconds. A simple spin-tracking model without the details of the COSY ring lattice was successful in reproducing these oscillations and demonstrating the sensitivity of the damping to the magnitude of the synchrotron motion of the beam particles. The model demonstrates that the characteristic features of measurements made in the presence of large synchrotron oscillations are distinct from the features of such measurements when made off resonance. These data were collected in preparation for a study of the spin coherence time, a beam property that needs to become long to enable a search for an electric dipole moment using a storage ring.

Published
2012
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14. Realization of Spin-dependent p-C Scattering in GEANT4 and Its Application To Storage Ring Experiment For pEDM

Author

Seongtae Park, Hoyong Jeong, E. J. Stephenson, Yannis K. Semertzidis, Eunil Won, and Eleni Petrakou

Subjects
Elastic scattering, Azimuth, Physics, Physics::Instrumentation and Detectors, Scattering, Beam tilt, Detector, Gas electron multiplier, Polarimeter, Nuclear Experiment, Storage ring, Computational physics
Abstract

The Center for Axion and Precision Physics Research (CAPP) of the Institute for Basic Science (IBS) is attempting to develop prototype polarimeter detector using gas electron multiplier (GEM) technology for the storage ring proton EDM (SR pEDM) experiment. Systematic errors in the polarimeter mainly come from geometric characteristics of the polarimeter and beam dynamics. Such as beam tilt, shift or detector misalignment etc. can be sources of errors. This investigation of systematic errors has been done with GEANT4 simulation package modified by ourselves. The modified GEANT4 can calculate spin-dependent hadron elastic cross-section of proton-carbon scattering, unlike the original one. This research will explain how to realize spin-dependent hadronic elastic scattering in the azimuth angle and demonstrate its application to the geometric error related systematic error study of polarimeter.

Published
2018

15. Phase measurement for driven spin oscillations in a storage ring

Author

S. Mey, P. Zupranski, L. Barion, M. S. Nioradze, A. Saleev, Martin Berz, D. Mchedlishvili, G. Guidoboni, E. J. Stephenson, Aleksandra Wrońska, R. Talman, Yu. N. Uzikov, H. Stockhorst, C. Weidemann, P. Wuestner, J. Slim, Dirk Heberling, D. Eversmann, P. Maanen, V. Schmidt, A. Stahl, B. Lorentz, W. Augustyniak, J. Pretz, K. Grigoryev, M. Bai, N.L. Lomidze, J. Hetzel, Alexander J. Silenko, H. Stroeher, Yu. Valdau, Nikolai N. Nikolaev, S. Dymov, D. Prasuhn, V. Hejny, Y. Semertzidis, E. Valetov, F. Mueller, Paolo Lenisa, H. Soltner, V. Shmakova, S. Chekmenev, A. Magiera, Rolf Stassen, F. Hinder, G.G. Macharashvili, G. Ciullo, G. Tagliente, A. Vassiliev, D. Grzonka, Ivan Koop, M. Gaisser, A.K. Kacharava, N. Hempelmann, Andreas Lehrach, A. Kulikov, I. Keshelashvili, M. D. Tabidze, Martin Rosenthal, Maria Zurek, F. Trinkel, Pia Thörngren Engblom, V. Kamerdzhiev, Y. Senichev, A. Nass, Frank Rathmann, Z. Bagdasarian, A. Pesce, Ralf Gebel, and Publica

Subjects
Physics, Physics and Astronomy (miscellaneous), Nuclear and High Energy Physics, Surfaces and Interfaces, Accelerator Physics (physics.acc-ph), 010308 nuclear & particles physics, Socio-culturale, FOS: Physical sciences, Polarization (waves), 01 natural sciences, 13.40.Em, 11.30.Er, 29.20.D, 29.20.dg, 29.20.db, Physical Sciences, 0103 physical sciences, lcsh:QC770-798, Fysik, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, Physics - Accelerator Physics, ddc:530, Radio frequency, Atomic physics, 010306 general physics, Storage ring
Abstract

Physical review accelerators and beams 21(4), 042002 (2018). doi:10.1103/PhysRevAccelBeams.21.042002, Published by American Physical Society, College Park, MD

Published
2018
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16. aCORN: An experiment to measure the electron-antineutrino correlation coefficient in free neutron decay

Author

Wangchun Chen, K. J. S. Stockton, I. Stern, A. Laptev, Thomas R. Gentile, H. Park, Jeffrey S. Nico, E. J. Stephenson, Gordon L. Jones, C. DeAngelis, J. Byrne, M. P. Mendenhall, W. K. Bauder, G. Darius, B. Collett, Maynard S. Dewey, G. Noid, B. G. Yerozolimsky, A. Komives, Fred E. Wietfeldt, W. A. Byron, Fred B. Bateman, M. T. Hassan, and C. Trull

Subjects
Physics, Physics - Instrumentation and Detectors, Correlation coefficient, Proton, 010308 nuclear & particles physics, media_common.quotation_subject, Measure (physics), FOS: Physical sciences, Instrumentation and Detectors (physics.ins-det), 01 natural sciences, Asymmetry, Article, Nuclear physics, Data acquisition, 0103 physical sciences, Neutron, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Instrumentation, Electron neutrino, media_common, Data reduction
Abstract

We describe an apparatus used to measure the electron-antineutrino angular correlation coefficient in free neutron decay. The apparatus employs a novel measurement technique in which the angular correlation is converted into a proton time-of-flight asymmetry that is counted directly, avoiding the need for proton spectroscopy. Details of the method, apparatus, detectors, data acquisition, and data reduction scheme are presented, along with a discussion of the important systematic effects., Comment: 21 pages, 25 figures

Published
2017

17. Phase Locking the Spin Precession in a Storage Ring

Author

Z. Bagdasarian, A. Pesce, Martin Berz, M. Bai, D. Mchedlishvili, D. Prasuhn, Ralf Gebel, E. Valetov, Dirk Heberling, Frank Rathmann, D. Grzonka, E. J. Stephenson, M. Żurek, P. Zupranski, H. Stockhorst, V. Shmakova, Andreas Lehrach, M. D. Tabidze, L. Barion, Aleksandra Wrońska, A. Stahl, B. Lorentz, J. Hetzel, Ivan Koop, D. Eversmann, G.G. Macharashvili, A. Saleev, P. Maanen, M. Gaisser, V. Kamerdzhiev, A. Magiera, G. Guidoboni, F. Müller, W. Augustyniak, P. Wüstner, J. Pretz, F. J. Etzkorn, G. Ciullo, A. Nass, S. Mey, I. Keshelashvili, H. Ströher, A. Kulikov, Nikolai N. Nikolaev, S. Chekmenev, S. Dymov, R. Stassen, F. Trinkel, C. Weidemann, J. Slim, V. Schmidt, Yu. Valdau, A. Silenko, N.L. Lomidze, Helmut Soltner, Y. Semertzidis, Martin Rosenthal, R. Talman, Yu. N. Uzikov, Paolo Lenisa, T. Hanraths, F. Hinder, A. Vassiliev, N. Hempelmann, K. Grigoryev, V. Hejny, G. Tagliente, A.K. Kacharava, and P. Thörngren Engblom

Subjects
Accelerator Physics (physics.acc-ph), Socio-culturale, FOS: Physical sciences, General Physics and Astronomy, 01 natural sciences, Beam Polarization, Sine wave, Nuclear magnetic resonance, storage rings, 0103 physical sciences, ddc:550, Accelerators, storage rings, Beam Polarization, EDM search, 010306 general physics, Physics, Spin polarization, 010308 nuclear & particles physics, Horizontal plane, Polarization (waves), Charged particle, Electric dipole moment, EDM search, Physics::Accelerator Physics, Physics - Accelerator Physics, Radio frequency, Atomic physics, Accelerators, Storage ring
Abstract

This letter reports the successful use of feedback from a spin polarization measurement to the revolution frequency of a 0.97 GeV/$c$ bunched and polarized deuteron beam in the Cooler Synchrotron (COSY) storage ring in order to control both the precession rate ($\approx 121$ kHz) and the phase of the horizontal polarization component. Real time synchronization with a radio frequency (rf) solenoid made possible the rotation of the polarization out of the horizontal plane, yielding a demonstration of the feedback method to manipulate the polarization. In particular, the rotation rate shows a sinusoidal function of the horizontal polarization phase (relative to the rf solenoid), which was controlled to within a one standard deviation range of $\sigma = 0.21$ rad. The minimum possible adjustment was 3.7 mHz out of a revolution frequency of 753 kHz, which changes the precession rate by 26 mrad/s. Such a capability meets a requirement for the use of storage rings to look for an intrinsic electric dipole moment of charged particles.

Published
2017

18. Measurement of the Electron-Antineutrino Angular Correlation in Neutron β Decay

Author

B. Collett, W. A. Byron, G. Darius, Fred E. Wietfeldt, E. J. Stephenson, M. P. Mendenhall, Jeffrey S. Nico, M. T. Hassan, A. Komives, C. DeAngelis, Gordon L. Jones, Maynard S. Dewey, and H. Park

Subjects
Physics, Proton, 010308 nuclear & particles physics, media_common.quotation_subject, General Physics and Astronomy, Electron, 01 natural sciences, Asymmetry, Coincidence, Nuclear physics, Time of flight, Angular correlation, 0103 physical sciences, High Energy Physics::Experiment, Neutron, Nuclear Experiment, 010306 general physics, Electron neutrino, media_common
Abstract

We report the first result for the electron-antineutrino angular correlation (a coefficient) in free neutron β decay from the aCORN experiment. aCORN uses a novel method in which the a coefficient is proportional to an asymmetry in proton time of flight for events where the β electron and recoil proton are detected in delayed coincidence. Data are presented from a 15 month run at the NIST Center for Neutron Research. We obtained a=-0.1090±0.0030(stat)±0.0028(sys), the most precise measurement of the neutron a coefficient reported to date.

Published
2017

19. The connection between zero chromaticity and long in-plane polarization lifetime in a magnetic storage ring

Author

M. Gaisser, V. Shmakova, B. Lorentz, A. Nass, G. Guidoboni, S. Mey, D. Zyuzin, Frank Rathmann, R. Maier, E. J. Stephenson, A.K. Kacharava, F. Trinkel, Aleksandra Wrońska, P. Wüstner, D. Mchedlishvili, J. Bsaisou, G. Ciullo, M. Żurek, Y. Senichev, Paolo Lenisa, F. Hinder, Yuri F. Orlov, S. Dymov, Martin Rosenthal, N. Hempelmann, H. Stockhorst, P. Thörngren Engblom, D. Eversmann, P. Maanen, A. Saleev, Z. Bagdasarian, A. Pesce, Ralf Gebel, D. Prasuhn, P. Kulessa, J. Pretz, V. Hejny, H. Ströher, I. Keshelashvili, Y. Semertzidis, Andreas Lehrach, C. Weidemann, Yu. Valdau, S. Chekmenev, and R. Talman

Subjects
Physics and Astronomy (miscellaneous), Nuclear and High Energy Physics, Surfaces and Interfaces, Accelerator Physics (physics.acc-ph), Physics - Instrumentation and Detectors, Socio-culturale, FOS: Physical sciences, Ring (chemistry), 01 natural sciences, law.invention, law, 0103 physical sciences, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, ddc:530, Chromaticity, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, Zero (complex analysis), Magnetic storage, Instrumentation and Detectors (physics.ins-det), Polarization (waves), Connection (mathematics), In plane, lcsh:QC770-798, Physics::Accelerator Physics, Physics - Accelerator Physics, Atomic physics
Abstract

In this paper, we demonstrate the connection between a magnetic storage ring with additional sextupole fields set so that the x and y chromaticities vanish and the maximizing of the lifetime of in-plane polarization (IPP) for a 0.97-GeV/c deuteron beam. The IPP magnitude was measured by continuously monitoring the down-up scattering asymmetry (sensitive to sideways polarization) in an in-beam, carbon-target polarimeter and unfolding the precession of the IPP due to the magnetic anomaly of the deuteron. The optimum operating conditions for a long IPP lifetime were made by scanning the field of the storage ring sextupole magnet families while observing the rate of IPP loss during storage of the beam. The beam was bunched and electron cooled. The IPP losses appear to arise from the change of the orbit circumference, and consequently the particle speed and spin tune, due to the transverse betatron oscillations of individual particles in the beam. The effects of these changes are canceled by an appropriate sextupole field setting., Comment: 18 pages, 18 figures, prepared for Phys. Rev. Accel. Beams

Published
2017
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20. A storage ring experiment to detect a proton electric dipole moment

Author

D. Kawall, Kyoko Makino, S. T. Park, Eric M. Metodiev, M. Bai, Andreas Lehrach, M. Grosse-Perdekamp, P. Fierlinger, A. Pesce, D. Moricciani, W. Meng, J. Talman, T. Roser, Andrew Ivanov, A.U. Luccio, Richard Talman, G. Venanzoni, M. Incagli, G. Guidoboni, J. Benante, Francois Méot, Konstantin Zioutas, Wolfram Fischer, Y. Giomataris, G. Fanourakis, Vadim Ptitsyn, S. Rescia, A. Sidorin, Jason Crnkovic, B. King, Michael Syphers, Selcuk Haciomeroglu, Richard Baartman, N. Tsoupas, B. I. Khazin, Yannis K. Semertzidis, Martin Berz, Yong-Ho Lee, Y. Senichev, G. Zavattini, Kevin Brown, J. Pretz, V. Tishchenko, T. J. V. Bowcock, S. K. Nayak, E. J. Stephenson, Ivan Koop, W.W. MacKay, Yuri F. Orlov, Alexey Lyapin, B. C. K. Casey, M. Blaskiewicz, C. Touramanis, A. N. Zelenski, R. Maier, M. Conte, Valeri Lebedev, G. Hoffstaetter, S. Baessler, E. Won, C. S. Özben, K. Vetter, Frank Rathmann, A. V. Fedotov, D. Raparia, A. Stahl, H. Huang, P. Pile, M. J. Lee, M. Gaisser, Shyh Yuan Lee, William J. Marciano, William Morse, B. Podobedov, D. M. Lazarus, P. Levi Sandri, Rasmus Larsen, Alexander J. Silenko, H. Kamal Sayed, Serge Andrianov, L. Miceli, N. Malitsky, P. Lenisa, Nikolaos Simos, H. Stroeher, S. Nagaitsev, S. Vlassis, Vassilis Anastassopoulos, E. J. Ramberg, Y. I. Kim, and V. Polychronakos

Subjects
Systematic error, Accelerator Physics (physics.acc-ph), Proton, Physics beyond the Standard Model, FOS: Physical sciences, p: electric moment, momentum, 01 natural sciences, High Energy Physics - Experiment, NO, Nuclear physics, Polarisation, Storage Rings, Fundamental Symmetries, Physics beyond Standard Model, High Energy Physics - Experiment (hep-ex), 0103 physical sciences, ddc:530, 010306 general physics, Instrumentation, Fundamental Symmetries, Polarisation, Physics, polarization, 010308 nuclear & particles physics, new physics, Magic (programming), Physics beyond Standard Model, storage ring, sensitivity, Electric dipole moment, electric moment [p], Storage Rings, Physics - Accelerator Physics, Storage ring, dipole, experimental results
Abstract

A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity of $10^{-29}e\cdot$cm by using polarized "magic" momentum $0.7$~GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the Standard Model at the scale of 3000~TeV., Comment: 8 pages, 3 figures

Published
2016
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21. aCORN: An experiment to measure the electron–antineutrino correlation in neutron decay

Author

A. Laptev, Fred E. Wietfeldt, C. Trull, J. Byrne, I. Stern, B. Collett, G. Noid, Gordon L. Jones, Jeffrey S. Nico, A. Komives, B. G. Yerozolimsky, E. J. Stephenson, and Maynard S. Dewey

Subjects
Physics, Nuclear and High Energy Physics, media_common.quotation_subject, Nuclear Theory, Cyclotron, Electron, Asymmetry, Beta decay, law.invention, Nuclear physics, Recoil, law, Physics::Accelerator Physics, Neutron, Nuclear Experiment, Instrumentation, Electron neutrino, Beam (structure), media_common
Abstract

The aCORN experiment is designed to make a precision (

Published
2009

22. RHIC polarimetry

Author

D. Svirida, A. Bazilevsky, T. Wise, Y. I. Makdisi, W. Haeberli, S. K. Dhawan, I. G. Alekseev, A. Nass, K. O. Eyser, A. Bravar, R. L. Gill, E. J. Stephenson, I. Nakagawa, Gerry Bunce, K. Yip, H. Okada, H. Huang, J. Wood, and A. N. Zelenski

Subjects
Physics, Proton, Physics::Instrumentation and Detectors, Scattering, Polarimetry, General Physics and Astronomy, Polarimeter, Polarization (waves), Kinetic energy, Nuclear physics, Recoil, General Materials Science, Physical and Theoretical Chemistry, Nuclear Experiment, Beam (structure)
Abstract

Polarimeters were developed to measure the polarization of the proton beam at RHIC in relative scale through the asymmetry measurement of the elastic proton-carbon scattering. Recoil carbon ions with kinetic energy of 400 ≤ E ≤ 900 keV were detected by silicon strip detectors installed at 90° with respect to the beam. The absolute polarization is given by normalizing against another polarimeter implemented at RHIC, namely a polarized hydrogen gas jet polarimeter. In this report, the details of polarization measurements, data analysis, and systematic uncertainties are discussed based on the data taken during √s = 200 GeV operation of Run05 at RHIC.

Published
2008

23. High-resolution study of Gamow-Teller excitations in theCa42(He3,t)Sc42reaction and the observation of a 'low-energy super-Gamow-Teller state'

Author

Juzo Zenihiro, Takashi Suzuki, Rhiannon Meharchand, Hooi Jin Ong, M. Csatlós, H. Okamura, Pedro Sarriguren, Hiroshi Matsubara, Atsushi Tamii, G. Perdikakis, C. L. Bai, B. Rubio, E. Estevez-Aguado, Carol Guess, Kenichi Yoshida, F. Molina, Y. Fujita, G. Susoy, T. Adachi, Kichiji Hatanaka, Y. Shimbara, J. M. Deaven, J. H. Thies, C. Scholl, Hisanori Fujita, J. Gulyás, Hiroyuki Sagawa, E. J. Stephenson, Takaharu Otsuka, Gianluca Colò, Hitoshi Nakada, Michio Honma, Alejandro Algora, D. Ishikawa, Katsuya Hirota, Remco Zegers, and A. Krasznahorkay

Subjects
Physics, Nuclear and High Energy Physics, Low energy, Fujita scale, High resolution, State (functional analysis), Atomic physics
Abstract

Y. Fujita et al.; 15 pags.; 6 figs.; 7 tabs.; PACS number(s): 21.10.Hw, 25.55.Kr, 27.40.+z, 25.40.Ep

Published
2015

24. New method for a continuous determination of the spin tune in storage rings and implications for precision experiments

Author

V. Hejny, H. Glückler, S. Chekmenev, Susanna Bertelli, Martin Berz, D. Mchedlishvili, Serge Andrianov, B. Lorentz, K. Grigoryev, Y. Semertzidis, G. Natour, B. Mariański, G.G. Macharashvili, K. Nowakowski, M. Zakrzewska, M. Contalbrigo, I. Keshelashvili, Paolo Lenisa, R. Talman, Frank Rathmann, E. Valetov, M. S. Nioradze, M. Statera, S. Dymov, A. Trzciński, D. Chiladze, Hans-Joachim Krause, J. Ritman, Andreas Lehrach, A. Saleev, Nikolai N. Nikolaev, H. Stockhorst, D. Hölscher, F. Hinder, V. Shmakova, S. Mey, C. Hanhart, C. Weidemann, J. Slim, A. Vassiliev, Ivan Koop, A. Khoukaz, Frank Goldenbaum, P. Zupranski, M. Bai, D. Eversmann, P. Maanen, M. D. Tabidze, M. Gaisser, N. Hempelmann, N.L. Lomidze, Alexander J. Silenko, A. Magiera, H. Straatmann, Dirk Heberling, R. Engels, D. Prasuhn, Andreas Nogga, W. Augustyniak, Z. Bagdasarian, J. Pretz, J. de Vries, A. Pesce, S. Krewald, D. Zyuzin, F. Trinkel, Ralf Gebel, A. Nass, Andrew Ivanov, G. Guidoboni, V. Kamerdzhiev, Kyoko Makino, Zbigniew Rudy, Colin Wilkin, Yu. Valdau, Ulf-G. Meißner, B. Kamys, P. Wüstner, Y. Senichev, Y. u. Uzikov, F.M. Esser, Andreas Wirzba, E. J. Stephenson, Aleksandra Wrońska, Olaf Felden, A.K. Kacharava, Rolf Stassen, G. Ciullo, P. Thörngren Engblom, R. Hipple, Rudolf Maier, J. Bsaisou, J. Hetzel, Achim Stahl, H. Soltner, H. Ströher, A. I. Kulikov, Werner Bernreuther, D. Grzonka, and Martin Rosenthal

Subjects
Accelerator Physics (physics.acc-ph), time reversal, Cyclotron, FOS: Physical sciences, General Physics and Astronomy, Socio-culturale, Electron, 01 natural sciences, 7. Clean energy, law.invention, Nuclear physics, Economica, law, 0103 physical sciences, ddc:550, Nuclear Experiment (nucl-ex), 010306 general physics, and other discrete symmetries, 11.30.Er Charge conjugation, Nuclear Experiment, Spin-½, Accelerator physics, Physics, Spin polarization, 010308 nuclear & particles physics, Charged particle, Dipole, parity, 29.20.dg Cyclotrons, 11.30.Er Charge conjugation, parity, time reversal, and other discrete symmetries,13.40.Em Electric and magnetic moments, 13.40.Em Electric and magnetic moments, Physics - Accelerator Physics, Atomic physics, 29.20.dg Cyclotrons, Storage ring
Abstract

A new method to determine the spin tune is described and tested. In an ideal planar magnetic ring, the spin tune - defined as the number of spin precessions per turn - is given by $\nu_s = \gamma G$ (gamma is the Lorentz factor, $G$ the magnetic anomaly). For 970 MeV/c deuterons coherently precessing with a frequency of ~120 kHz in the Cooler Synchrotron COSY, the spin tune is deduced from the up-down asymmetry of deuteron carbon scattering. In a time interval of 2.6 s, the spin tune was determined with a precision of the order $10^{-8}$, and to $1 \cdot 10^{-10}$ for a continuous 100 s accelerator cycle. This renders the presented method a new precision tool for accelerator physics: controlling the spin motion of particles to high precision is mandatory, in particular, for the measurement of electric dipole moments of charged particles in a storage ring., Comment: 6 pages, 6 figures

Published
2015

25. Measurement of the analyzing power AN in pp elastic scattering in the CNI region with a polarized atomic hydrogen gas jet target

Author

T. Wise, A. Nass, W. Haeberli, R. L. Gill, Satish Dhawan, O. Jinnouchi, G. Bunce, E. J. Stephenson, I. G. Alekseev, Alexander Khodinov, A. N. Zelenski, A. Bravar, Y. I. Makdisi, Hiroyuki Okada, Norio Saito, and D. N. Svirida

Subjects
Physics, Elastic scattering, Nuclear and High Energy Physics, Jet (fluid), Proton, 010308 nuclear & particles physics, media_common.quotation_subject, Momentum transfer, Hadron, 01 natural sciences, Asymmetry, Nuclear physics, Amplitude, 0103 physical sciences, High Energy Physics::Experiment, Spin-flip, Nuclear Experiment, 010306 general physics, media_common
Abstract

A precise measurement of the analyzing power A N in proton–proton elastic scattering in the region of 4-momentum transfer squared 0.001 | t | 0.032 ( GeV / c ) 2 has been performed using a polarized atomic hydrogen gas jet target and the 100 GeV/ c RHIC proton beam. The interference of the electromagnetic spin-flip amplitude with a hadronic spin-nonflip amplitude is predicted to generate a significant A N of 4–5%, peaking at − t ≃ 0.003 ( GeV / c ) 2 . This kinematic region is known as the Coulomb nuclear interference region. A possible hadronic spin-flip amplitude modifies this calculable prediction. We present the first precise result of the CNI asymmetry and shape as a function of t . Our data are well described by the CNI prediction with the electromagnetic spin-flip alone and do not support the presence of a large hadronic spin-flip amplitude.

Published
2006

26. Spin Dependence in Polarized and Elastic Scattering at Very Low Momentum Transfer t at RHIC

Author

Ahovi Kponou, Satish Dhawan, O. Jinnouchi, J. Wood, Wuzheng Meng, G. Igo, Alexander Khodinov, A. Nass, W. Haeberli, Hiroyuki Okada, Y. I. Makdisi, R. L. Gill, C. A. Whitten, A. Bravar, G. Bunce, H. Huang, E. J. Stephenson, I. G. Alekseev, A. N. Zelenski, Norio Saito, H. M. Spinka, T. Wise, K. Kurita, D. G. Underwood, and D. N. Svirida

Subjects
Physics, Elastic scattering, Nuclear and High Energy Physics, Particle physics, Proton, Nuclear Theory, High Energy Physics::Phenomenology, Momentum transfer, Hadron, Observable, Atomic and Molecular Physics, and Optics, Nuclear physics, Amplitude, Coulomb, High Energy Physics::Experiment, Nuclear Experiment, Spin-½
Abstract

Interference phenomena in (polarized) hadron collisions have often led to spectacular spin effects in the final state. These effects are expressed in terms of the spin observables, like the analyzing power AN. The interference of the electromagnetic spin-flip amplitude with a hadronic spin-nonflip amplitude in the elastic scattering of hadrons generates a significant AN at very low t ( 0.001 | t | 0.01 ( GeV / c ) 2 ) . This kinematical region is referred to as the Coulomb Nuclear Interference (CNI) region. A possible hadronic spin-flip amplitude can substantially modify the magnitude and shape of AN, which otherwise is exactly calculable. First results on AN in polarized proton-proton elastic scattering in the CNI region at 100 GeV from the 2004 polarized proton run at RHIC are presented. New results on AN in the elastic scattering of polarized protons off a carbon target over a wide energy range from 4 GeV to 100 GeV from AGS and RHIC are presented, as well. These results allow us to further study the spin dependence in elastic scattering and the mechanisms that generate these effects.

Published
2005

27. Development of a tagged neutron facility at intermediate energies

Author

S. E. Vigdor, Todd W. Hossbach, Todd E. Peterson, Y. Zhou, L. C. Bland, Nils Olsson, W. W. Jacobs, C. E. Allgower, T. Rinckel, B. Bergenwall, A. Klyachko, T. Kinashi, Christer Johansson, J. Rapaport, M. Planinic, S. W. Wissink, P Nadel-Turonski, Joakim Klug, Stephan Pomp, Leif Nilsson, Jan Blomgren, E. J. Stephenson, J. Doskow, and Udomrat Tippawan

Subjects
Elastic scattering, Bonner sphere, Physics, Nuclear and High Energy Physics, Proton, Nuclear Theory, Neutron scattering, Neutron time-of-flight scattering, Nuclear physics, Neutron cross section, Physics::Accelerator Physics, Neutron detection, Neutron, Nuclear Experiment, Instrumentation
Abstract

A unique experimental facility has been developed to measure absolute neutron scattering cross-sections through the use of tagged intermediate-energy neutrons. The neutrons are produced via the reaction p+d→n+2p with an electron-cooled circulating proton beam of 200 MeV bombarding energy incident on a deuterium gas jet target. The “tagging” of the neutrons is accomplished by detection of the associated recoil protons in an array of silicon microstrip detectors located in vacuum. The detection of two protons in coincidence signals the production of a neutron, while energy and position measurements on the recoil protons allow for reconstruction of the four-momentum of the neutron, and its impact position on a secondary target, on an event-by-event basis. Performance characteristics of this facility are presented, and its future application to an absolute measurement of the np elastic scattering cross-section is described.

Published
2004

28. An update from STAR—using strangeness to probe relativistic heavy ion collisions

Author

V. V. Belaga, V. Grigoriev, Z. Xu, Sergey Voloshin, P. Sorensen, R. L. Ray, E. Potrebenikova, M.A. Kramer, R. V. Cadman, Peter Graham Jones, K. J. Foley, F. Laue, A. Szanto de Toledo, T. Ljubicic, Jianhong Wu, H. Caines, E. Sugarbaker, T. Pawlak, V. L. Rykov, Frank Jm Geurts, L. Didenko, G. Eppley, J. Porter, I. Sakrejda, J. Balewski, J. Baudot, Claude Andre Pruneau, J. Pluta, R. Willson, D. G. Underwood, F. Meissner, A. Stolpovsky, R. Lednický, V. A. Nikitin, T. Ullrich, Y. V. Zanevski, R. Zoulkarneev, L. Kotchenda, S. Kabana, K. E. Shestermanov, Jinghui Yang, A. Lebedev, Q. J. Liu, M. M. de Moura, K. Schweda, T. J. Hallman, T. J. M. Symons, S. V. Razin, L. Gaudichet, J. Kiryluk, M. L. Miller, B. Choi, R. E. Tribble, R. S. Longacre, H. Bichsel, M. Castro, Jay Roberts, S. R. Klein, C. Struck, O. Barannikova, D. L. Olson, Gerald W Hoffmann, Yu-Gang Ma, A. Tai, P. Szarwas, J. Takahashi, J. Putschke, G. Odyniec, D. Thein, Alexander Kovalenko, O. A. Grachov, X. Dong, C. L. Kunz, C. F. Moore, J. W. Watson, A. Bravar, Joseph Adams, A. A. Derevschikov, L. V. Nogach, A. H. Tang, R.Kh. Kutuev, J. Berger, S. P. Chernenko, A. Ogawa, M. Kopytine, J. Amonett, W. J. Llope, X. L. Wang, Julien Faivre, J. Klay, V. B. Dunin, A. V. Brandin, Zhongyukun Xu, Thomas A. Trainor, A. Ridiger, Thorsten Sven Kollegger, D. Reichhold, D. Magestro, L. Ruan, V. Trofimov, M. Tokarev, A. Rose, V. Emelianov, A. I. Pavlinov, D. Keane, T. J. Humanic, R. Witt, F. Liu, M. B. Tonjes, S. Heppelmann, D. Flierl, Matthew J. Anderson, Marie Germain, R. P. Scharenberg, S. M. Guertin, S L Huang, Alexandre Alarcon Do Passo Suaide, B. Lasiuk, J. H. Thomas, H. S. Matis, L. Martin, David Lynn, H. Long, Nikolai Smirnov, R. Stock, J. Mitchell, L. G. Efimov, G. Skoro, S. E. Vigdor, G. Igo, J. Zoulkarneeva, Christian Claude Kuhn, V. Morozov, I.A. Savin, W. W. Jacobs, D. D. Koetke, V. Petrov, J. E. Draper, A. N. Zubarev, C. A. Gagliardi, E. Hjort, B. E. Bonner, J. Lauret, B. D. Anderson, O. D. Tsai, D. Hardtke, J. Fu, B. K. Srivastava, Yu Chen, R. D. Majka, N. T. Porile, M. Messer, M.M. Corral, G. S. Averichev, H. H. Wieman, J. Sowinski, S. Stanislaus, J. Marx, Z. M. Wang, M. A. Vasiliev, T. Herston, B. Surrow, S. Margetis, J. Schambach, P. Fachini, J. P. Coffin, O. V. Rogachevski, J. Gans, Boris Hippolyte, H. Ward, W. Christie, J. C. Dunlop, A. I. Kulikov, R. Manweiler, J. Carroll, P. Seyboth, Masashi Kaneta, Fuqiang Wang, H. M. Spinka, Sevil Salur, M. Oldenburg, T. Dietel, W. M. Zhang, Andrey Vasiliev, A. M. Poskanzer, Zubayer Ahammed, J. G. Ma, Y. Panebratsev, M. Shao, M. J. LeVine, V. Ghazikhanian, D. Grosnick, S. Lange, G. Rai, Janet Elizabeth Seger, A. A. Kuznetsov, V. I. Yurevich, J. L. Romero, C. P. Lansdell, Yu A. Matulenko, Frank Simon, S.J. Lindenbaum, L. S. Schroeder, E. Yamamoto, E. Finch, T W Henry, I. Zborovský, R.J.M. Snellings, B. Erazmus, R. Wells, A. P. Meschanin, M. Heinz, Lee Stuart Barnby, F. Retiere, Y. Fisyak, M. Horsley, C Whitten, Ian Johnson, N. G. Minaev, N. Xu, P. Filip, C Li, B. Stringfellow, D. Cebra, N. Schmitz, G. D. Westfall, E. Shahaliev, S. Trentalange, W. A. Love, Malgorzata Anna Janik, Yu Melnick, Marcelo Gameiro Munhoz, D. J. Prindle, H. Zhang, E. J. Stephenson, M. A. Lisa, A. Billmeier, J. G. Cramer, R. Fatemi, K. Krueger, M. Cherney, Thomas Michael Cormier, T. S. McShane, P. Nevski, J. E. Gonzalez, M. Lopez-Noriega, Adam Ryszard Kisiel, Michal Sumbera, H. J. Crawford, A. Ishihara, G. Renault, J. Engelage, C. Suire, V. Faine, John N. Wood, J. Castillo, S. W. Wissink, J. M. Landgraf, V. A. Okorokov, M. Strikhanov, G. Rakness, M. Guedon, A. M. VanderMolen, Guy Paic, E. G. Judd, A. Chikanian, S. S. Shimanskii, P.A. Zolnierczuk, Christina Markert, J. Sandweiss, Z. Liu, A. Boucham, D. Arkhipkin, S. Bekele, C. Roy, C. O. Blyth, A. Klyachko, Vladimir Tikhomirov, P. Chaloupka, B. Norman, G. Van Buren, T. W. Ludlam, J. M. Nelson, W. Peryt, H. G. Ritter, H. Z. Huang, Morton Kaplan, X. Z. Cai, R. Bellwied, A. S. Konstantinov, L. C. Bland, L. Liu, V. M. Leontiev, D. Seliverstov, A. Schüttauf, Olivier Ravel, A. S. Hirsch, Peter Martin Jacobs, P. Kravtsov, C. Adler, M. A. C. Lamont, S. B. Nurushev, Z. Milosevich, Jeffrey G. Reid, Hao-Ze Chen, M. Calderon De La Barca Sanchez, Subhasis Chattopadhyay, Q. Li, J. W. Harris, N.D. Gagunashvili, A Cardenas, Z P Zhang, E. Gushin, G. J. Kunde, P. Yepes, V. Eckardt, V. Perevoztchikov, K. Filimonov, Sergey Panitkin, S. U. Pandey, and A. E. Yakutin

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, Particle physics, Strange quark, media_common.quotation_subject, Hadron, Elementary particle, Kinematics, Decoupling (cosmology), Strangeness, Asymmetry, Nuclear physics, Nuclear Experiment, media_common
Abstract

An overview of the strangeness measurements made by the STAR collaboration at RHIC for Au-Au collisions at √s NN = 130 and 200 GeV plus p-p collisions at √s NN = 200 GeV is presented. A wealth of information has been generated on the kinematics and scale of strange particle production by this experiment. When viewed in combination a picture emerges of particles demonstrating a surprisingly high degree of collective motion, suggestive of strong internal pressure within the source which builds up rapidly. The non-resonance yields are consistent with statistical hadron formation. Although there appears to be a rapid decoupling of the source, resonance particle measurements show signs of rescattering during the hadronic phase. Meanwhile the observed suppression of high momentum probes and their large azimuthal asymmetry indicate that this hot dense matter has significant interactions with particles moving through it.

Published
2003

29. Strange antiparticle-to-particle ratios at mid-rapidity in =130 GeV Au+Au collisions

Author

M. Calderon De La Barca Sanchez, A. Lebedev, R. V. Cadman, Vitaly Okorokov, Frank Jm Geurts, Q. Li, Adam Ryszard Kisiel, T. J. Humanic, H. J. Crawford, I.A. Savin, N. T. Porile, R. Fatemi, Y. Panebratsev, V. Trofimov, C. A. Gagliardi, Q. J. Liu, C. A. Whitten, K. Krueger, G. Rai, Yu A. Matulenko, T. Herston, Fuqiang Wang, C. E. Allgower, M. Horsley, B. Stringfellow, S. Lange, S. J. Lindenbaum, N. Xu, J. Balewski, M. Cherney, H. G. Ritter, Thomas Michael Cormier, Claude Andre Pruneau, W. Christie, G. D. Westfall, A. Billmeier, P. Nevski, J. W. Harris, Malgorzata Anna Janik, V. I. Yurevich, C. Struck, J. Takahashi, J. Putschke, J. W. Watson, A. I. Kulikov, A. Ridiger, Thorsten Sven Kollegger, J. G. Cramer, K. Schweda, T. Ullrich, J. H. Thomas, A. S. Hirsch, Frank Simon, C. Roy, P. Kravtsov, Masashi Kaneta, A. M. Poskanzer, A. Ogawa, R. Bellwied, Thomas A. Trainor, E. Yamamoto, C. Adler, R. Zoulkarneev, A. Stolpovsky, L. Kotchenda, B. Erazmus, A. S. Konstantinov, A. Tai, R. S. Longacre, W. M. Zhang, Andrey Vasiliev, R. Lednický, V. A. Nikitin, Joseph Adams, J. Amonett, V. Grigoriev, T. Dietel, K. E. Shestermanov, R. L. Ray, M. Kramer, A. Klyachko, E. Potrebenikova, M. Heinz, Lee Stuart Barnby, J. Klay, E. Gushin, G. J. Kunde, M. Castro, M. Oldenburg, P. Yepes, V. Eckardt, E. Hjort, D. Magestro, B. Choi, Jeffrey G. Reid, D. Cebra, T. S. McShane, V. Emelianov, Vladimir Tikhomirov, D. Keane, S. Heppelmann, D. Flierl, A. H. Tang, F. Retiere, T. Ljubicic, Nikolai Smirnov, Yu Melnick, N. G. Minaev, Z. J. Xu, R. Stock, J. Mitchell, H. Caines, W. A. Love, L. G. Efimov, Marcelo Gameiro Munhoz, Alexander Kovalenko, L. V. Nogach, Vladimir Petrov, R. P. Scharenberg, S. P. Chernenko, Yu. Ivanshin, V. L. Rykov, Janet Elizabeth Seger, D. J. Prindle, W. J. Llope, G. S. Averichev, L. Martin, H. Zhang, J. Carroll, S. Trentalange, Guy Paic, A. Chikanian, S. S. Shimanskii, G. Igo, E. J. Stephenson, J. N. Marx, B. E. Bonner, Marie Germain, A. Cardenas, O. D. Tsai, H. S. Matis, G. Skoro, G. Rakness, W. W. Jacobs, B. D. Anderson, M. A. Lisa, A. A.P. Suaide, S. M. Guertin, J. E. Draper, Julien Faivre, A. Rose, J. Lauret, L. C. Bland, A. Boucham, B. Lasiuk, V. Ghazikhanian, A. V. Brandin, H. Bichsel, Yu Chen, W. S. Deng, H. Ward, V. Perevoztchikov, G. Odyniec, K. Filimonov, David Lynn, S. E. Vigdor, Christian Claude Kuhn, A. A. Kuznetsov, L. Liu, V. M. Leontiev, Olivier Ravel, Sergey Panitkin, M. Planinic, S. Bekele, J. P. Coffin, O. V. Rogachevski, D. Reichhold, A. I. Pavlinov, F. Liu, M. B. Tonjes, G. Eppley, Subhasis Chattopadhyay, E. G. Judd, A. N. Zubarev, Matthew J. Anderson, E. Sugarbaker, H. Z. Huang, J. Pluta, J. L. Romero, E. Finch, A. Ishihara, V. Morozov, M. Messer, Sevil Salur, Morton Kaplan, S. Margetis, O. A. Grachov, J. G. Ma, B. Surrow, S. U. Pandey, F. Meissner, A. E. Yakutin, C. P. Lansdell, R. Wells, R.J.M. Snellings, P. Seyboth, D. Hardtke, R. D. Majka, Sergey Voloshin, K. J. Foley, G. Van Buren, A. P. Meschanin, N.D. Gagunashvili, A. Bravar, J. Sowinski, R. K. Kutuev, P. Fachini, R. E. Tribble, J. Schambach, Gerald W Hoffmann, H. M. Spinka, T. W. Ludlam, T. W. Henry, J. Baudot, I. Sakrejda, J. M. Nelson, Y. V. Zanevski, N. Schmitz, E. Shahaliev, I. Zborovský, W. Peryt, M. Lopez-Noriega, M. M. de Moura, Y. Fisyak, Ian Johnson, M. L. Miller, D. Seliverstov, A. Schüttauf, M. Guedon, A. M. VanderMolen, Michael A. Thompson, P. Szarwas, V. V. Belaga, Peter Martin Jacobs, Michal Sumbera, G. Renault, M. A. C. Lamont, S. B. Nurushev, Z. Milosevich, C. Suire, P. Chaloupka, V. Faine, J. Castillo, P. Sorensen, S. W. Wissink, Peter Graham Jones, L. Didenko, Jinghui Yang, S. R. Klein, O. Barannikova, D. L. Olson, A. A. Derevschikov, D. Thein, H. Long, M. Kopytine, M. Tokarev, M.M. Corral, H. H. Wieman, S. V. Razin, L. Gaudichet, J. Kiryluk, Jay Roberts, C. L. Kunz, F. Laue, A. Szanto de Toledo, C. F. Moore, T. Pawlak, J. C. Dunlop, J. Porter, Zubayer Ahammed, M. J. LeVine, R. Willson, D. G. Underwood, L. S. Schroeder, R. Witt, J. Fu, B. K. Srivastava, I. M. Vasilevski, T. J. Hallman, J. Gans, T. J. M. Symons, Boris Hippolyte, J. Berger, V. B. Dunin, C. O. Blyth, B. Norman, J. Engelage, John N. Wood, J. M. Landgraf, M. Strikhanov, Christina Markert, J. Sandweiss, and Z. Liu

Subjects
Quark, Physics, Nuclear and High Energy Physics, Strange quark, Antiparticle, Particle physics, STAR, Hyperon, Strangeness, Baryochemical potential, Nuclear physics, Baryon, Relativistic heavy-ion collisions, Antibaryon-to-baryon ratios, Rapidity, Nucleon
Abstract

Values of the ratios in the mid-rapidity yields of Λ / Λ =0.71±0.01( stat. )±0.04( sys. ) , Ξ + / Ξ − =0.83±0.04( stat. )±0.05( sys. ) , Ω + / Ω − =0.95±0.15( stat. )±0.05( sys. ) and K + /K − =1.092±0.023(combined) were obtained in central s NN =130 GeV Au+Au collisions using the STAR detector. The ratios indicate that a fraction of the net-baryon number from the initial system is present in the excess of hyperons over antihyperons at mid-rapidity. The trend in the progression of the baryon ratios, with increasing strange quark content, is similar to that observed in heavy-ion collisions at lower energies. The value of these ratios may be related to the charged kaon ratio in the framework of simple quark-counting and thermal models.

Published
2003

30. The STAR endcap electromagnetic calorimeter

Author

A. M. Vander Molen, I. Cyliax, N.D. Gagunashvili, A. Klyachko, G. Eppley, J. Sowinski, A. R. Baldwin, R. V. Cadman, Vladimir Tikhomirov, R. L. Brown, S. W. Wissink, J. W. Watson, S. Shimansky, W. Hunt, R. E. Tribble, M. Tokarev, A. Yokosawa, S. E. Vigdor, V. I. Yurevich, K. Solberg, L. C. Bland, H. Spinka, W. W. Jacobs, O. V. Rogachevski, B. D. Anderson, G. Rakness, D. G. Underwood, E. J. Stephenson, Gary Westfall, C. A. Gagliardi, T. J. Hallman, J. Puskar-Pasewicz, S. V. Razin, J. Balewski, M. Planinic, A. Ogawa, M. Belt-Tonjes, V. B. Dunin, L. G. Efimov, A. N. Zubarev, Y. Panebratsev, W. Christie, A. I. Kulikov, W. M. Zhang, K. Krueger, and C. E. Allgower

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Photon, Meson, Physics::Instrumentation and Detectors, Detector, Hadron, Electron, Particle detector, Particle identification, Nuclear physics, Pseudorapidity, High Energy Physics::Experiment, Nuclear Experiment, Instrumentation
Abstract

The STAR endcap electromagnetic calorimeter will provide full azimuthal coverage for high-pT photons, electrons and electromagnetically decaying mesons over the pseudorapidity range 1.086⩽η⩽2.00. It includes a scintillating-strip shower-maximum detector to provide π0/γ discrimination and preshower and postshower layers to aid in distinguishing between electrons and charged hadrons. The triggering capabilities and coverage it offers are crucial for much of the spin physics program to be carried out in polarized proton–proton collisions.

Published
2003

31. Strangeness in Au$plus$Au collisions at $\surd$sNN $equal$ 130 GeV observed with the STAR detector

Author

Y. Fisyak, A. Ogawa, Ian Johnson, Christophe Pierre Suire, A. H. Tang, P. Seyboth, Guy Paic, A. Chikanian, S. S. Shimanskii, A. Ridiger, K. Schweda, G. Eppley, A. Stolpovsky, H. Hümmler, Marie Germain, T. S. McShane, M. Šumbera, J. Pluta, V. Ghazikhanian, R. S. Longacre, Michael A. Thompson, L. Kotchenda, C. Struck, A. A.P. Suaide, S. Heppelmann, D. Flierl, A. I. Pavlinov, B. E. Bonner, J. L. Romero, O. D. Tsai, L. Lakehal-Ayat, G. Van Buren, J. Takahashi, J. W. Watson, L. Martin, F. Liu, M. B. Tonjes, A. N. Zubarev, G. Igo, A. Boucham, R. E. Tribble, Gerald W Hoffmann, S. Lee Barnby, M. Castro, Torre Wenaus, R. K. Kutuev, V. Morozov, M. Messer, V. Grigoriev, Q. Li, J. Grabski, K. Krueger, V. S. Shvetcov, Q. J. Liu, C. A. Whitten, Thomas A. Trainor, J. Berger, J. E. Draper, V. Faine, R. L. Ray, J. Castillo, E. Potrebenikova, J. M. Nelson, D. Hardtke, P. Fachini, A. M. van der Molen, S. Bekele, W. Peryt, R. D. Majka, R. V. Cadman, S. W. Wissink, E. Finch, Frank Jm Geurts, B. Choi, B. D. Anderson, J. N. Marx, A. P. Meschanin, C. E. Allgower, V. V. Belaga, J. Fu, B. K. Srivastava, I. M. Vasilevski, Alexander Kovalenko, J. Sowinski, J. Schambach, T. Ljubicic, H. Caines, W. S. Deng, J. P. Coffin, O. V. Rogachevski, V. Perevoztchikov, K. Filimonov, L. V. Nogach, V. L. Rykov, M. Cherney, A. Ishihara, V. B. Dunin, W. Christie, J. Gans, P. Sorensen, S. Lange, E. Sugarbaker, Thomas Michael Cormier, V. Trofimov, Peter Graham Jones, A. I. Kulikov, S. J. Lindenbaum, Yu Chen, H. Z. Huang, Boris Hippolyte, Masashi Kaneta, R. Wells, Morton Kaplan, W. M. Zhang, Andrey Vasiliev, J. Balewski, J. G. Cramer, P. Nevski, Sergey Panitkin, J. C. Dunlop, Claude Andre Pruneau, Sergey Voloshin, L. Didenko, F. Meissner, D. Seliverstov, A. Schüttauf, Jinghui Yang, T. Ullrich, G. lo Curto, Janet Elizabeth Seger, R. Zoulkarneev, K. J. Foley, L. C. Bland, Peter Martin Jacobs, Subhasis Chattopadhyay, Zubayer Ahammed, M. Kramer, K. Turner, M. Guedon, M. J. LeVine, S. Radomski, S. R. Klein, Y. Panebratsev, T. J. Humanic, C. Roy, S. U. Pandey, A. E. Yakutin, O. Barannikova, D. L. Olson, I.A. Savin, N. T. Porile, J. W. Harris, R. P. Scharenberg, G. Rai, M. A. C. Lamont, S. B. Nurushev, Z. Milosevich, Mingshui Chen, F. Retiere, A. Klyachko, A. A. Derevschikov, A. Lebedev, S. Margetis, N. Schmitz, H. S. Matis, A. C. Saulys, F. Laue, Yu A. Matulenko, M. Horsley, E. Gushin, G. J. Kunde, Vladimir Tikhomirov, N. G. Minaev, Vladimir Petrov, E. Shahaliev, P. Yepes, V. Eckardt, O. A. Grachov, A. Szanto de Toledo, B. Stringfellow, Z. J. Xu, S. P. Chernenko, L. S. Schroeder, E. G. Judd, Adam Ryszard Kisiel, N. Xu, W. J. Llope, S. Trentalange, J. Baudot, S. V. Razin, E. Hjort, L. Gaudichet, H. J. Crawford, A. Cardenas, J. Kiryluk, N.D. Gagunashvili, Y. V. Zanevski, T. Pawlak, G. D. Westfall, J. Carroll, W. W. Jacobs, Jay Roberts, Malgorzata Anna Janik, J. Porter, B. Lasiuk, C. L. Kunz, M. Lopez-Noriega, H. Long, C. F. Moore, C. P. Lansdell, R.J.M. Snellings, R. Witt, R. Willson, A. Tai, D. G. Underwood, J. Amonett, G. Skoro, M. Heffner, J. Klay, M. Oldenburg, V. Emelianov, D. Keane, D. Reichhold, R. Lednický, Nikolai Smirnov, R. Stock, J. Mitchell, L. G. Efimov, T. J. Hallman, T. J. M. Symons, Yu. Ivanshin, V. A. Nikitin, H. Ward, A. S. Hirsch, M. de la Calderón Barca Sánchez, A. A. Kuznetsov, L. Liu, P. Kravtsov, V. M. Leontiev, Olivier Ravel, C. Adler, K. E. Shestermanov, H. G. Ritter, R. Bellwied, Jeffrey G. Reid, A. S. Konstantinov, B. Erazmus, D. Cebra, Yu Melnick, V. A. Moiseenko, Marcelo Gameiro Munhoz, D. J. Prindle, A. V. Brandin, H. Zhang, E. J. Stephenson, M. A. Lisa, H. M. Spinka, J. H. Thomas, H. Bichsel, S. E. Vigdor, G. Odyniec, G. S. Averichev, Christian Claude Kuhn, Matthew J. Anderson, David Lynn, Lee Stuart Barnby, C. O. Blyth, A. M. Poskanzer, W. A. Love, B. Norman, I. Sakrejda, Vitaly Okorokov, M. Tokarev, H. H. Wieman, J. Engelage, John N. Wood, J. M. Landgraf, M. M. de Moura, M. Strikhanov, M. L. Miller, Christina Markert, J. Sandweiss, Z. Liu, P. Szarwas, E. Yamamoto, C. A. Gagliardi, T. Herston, Fuqiang Wang, V. I. Yurevich, and I. Zborovský

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, High Energy Physics::Phenomenology, Nuclear Theory, Hadron, Strangeness production, Astrophysics::Cosmology and Extragalactic Astrophysics, Strangeness, Spectral line, Nuclear physics, Baryon, Transverse plane, Pion, High Energy Physics::Experiment, Nuclear Experiment, STAR detector
Abstract

The STAR detector has made a variety of measurements of strange and other hadronic species in Au+Au collisions at s N N = 130 GeV. A comparison of kaon and pion production enables an examination of the systematics of strangeness production with energy by comparing them to lower energy collisions. Anti-baryon to baryon ratios indicate a much reduced net-baryon density and transverse momentum spectra show that a picture of transverse expansion seems appropriate.

Published
2002

32. Realization of matching conditions for high-resolution spectrometers

Author

G. P. A. Berg, Y. Shimbara, Hideki Ueno, A.D. Bacher, T. Shinada, Yoshitaka Fujita, Takahiro Kawabata, M. Yosoi, Kichiji Hatanaka, Harutaka Sakaguchi, E. J. Stephenson, Tetsuo Noro, C. C. Foster, Hisanori Fujita, and K. Hara

Subjects
Physics, Nuclear and High Energy Physics, Matching (statistics), Spectrometer, business.industry, Scattering, Kinematics, Optics, Beamline, Dispersion (optics), Physics::Accelerator Physics, Nuclear Experiment, business, Focus (optics), Instrumentation, Beam (structure)
Abstract

For precise measurements of nuclear-reaction spectra using a beam from an accelerator, a high-resolution magnetic spectrometer is a powerful tool. The full capability of a magnetic spectrometer, however, can be achieved only if the characteristics of the beam coming from the accelerator are matched to those required by the spectrometer by properly adjusting the beam line conditions. The matching methods, lateral dispersion matching, focus matching and also the kinematic correction compensate the spectrum line-broadening effects caused by the beam momentum spread and reaction kinematics. In addition, angular dispersion matching should be performed if good resolution of the scattering angle is important. Diagnostic methods developed to realize these matching conditions for the spectrometers K600 at IUCF and Grand Raiden at RCNP are presented.

Published
2002

33. Isospin Symmetry in the Structure Study of Unstable Nuclei

Author

E. J. Stephenson, Tetsuo Noro, A.D. Bacher, Hideki Ueno, T. Black, C. C. Foster, Hisanori Fujita, K. Katori, H. Fujimura, G. P. A. Berg, Y. Shimbara, M. Yosoi, D. A. Roberts, W.R. Lozowski, Takahiro Kawabata, T. Yamanaka, Y. Fujita, J. W. Jänecke, Kichiji Hatanaka, Junichiro Kamiya, and K. Hara

Subjects
Physics, Physics and Astronomy (miscellaneous), Structure (category theory), Symmetry (physics), Good quantum number, medicine.anatomical_structure, Classical mechanics, Nucleosynthesis, Isospin, Excited state, medicine, Mirror nuclei, Atomic physics, Nucleus
Abstract

Assuming isospin T is a good quantum number, the analog states of the low-lying states in T z = ′ (T 0 +1) nuclei can be found as excited T 0 +1 states in T z = ′T 0 nuclei. Therefore, if To + 1 states are identified in theexcited region of T z = ′T 0 nuclei, the structure of unstable nuclei with T z = ′(T 0 + 1) can be deduced. We measured and compared the transition strengths to pairs of excited analog states in inelastic and charge-exchange reactions on the same target nucleus. The T values of these analog states were identified by using the fact that the transition strengths to them are different depending on T. The identification of T = ½ and 3/2 nature of analog M1 and GT states in the mirror nuclei pair 2 7 Al and 2 7 Si is reported by comparing the transition strengths in high-resolution 2 7 Al(p,p') and 2 7 Al( 3 He, t) 2 7 Si reactions at 0°. The identified T = 3/2 states are analogous to the low-lying states of 2 7 Mg, which plays an important role in rp-process of nucleosynthesis.

Published
2002

34. Measuring the polarization of a rapidly precessing deuteron beam

Author

P. Lenisa, Z. Bagdasarian, A. Pesce, Ralf Gebel, B. Lorentz, P. Thörngren Engblom, J. Dietrich, Hans Stockhorst, Frank Rathmann, V. Hejny, R. Maier, S. Bertelli, E. J. Stephenson, L. Magallanes, V. Kamerdzhiev, Yu. Valdau, G. Fanourakis, H. Ströher, C. Weidemann, A. Nass, V. Shmakova, B. Gou, Richard Talman, D. Chiladze, Andreas Lehrach, D. Eversmann, G. Ciullo, M. Gaisser, D. Mchedlishvili, William Morse, S. Dymov, P. Wüstner, D. Oellers, G. Guidoboni, Yannis K. Semertzidis, D. Prasuhn, A.K. Kacharava, and J. Pretz

Subjects
Accelerator Physics (physics.acc-ph), Physics, 29.20.D- Cyclic accelerators and storage rings, 29.27.Hj Polarized beams, 29.27.Ac Beam injection and extraction, Nuclear and High Energy Physics, Polarization rotator, Physics and Astronomy (miscellaneous), Spin polarization, Linear polarization, business.industry, FOS: Physical sciences, Surfaces and Interfaces, Polarization (waves), Electric dipole moment, Optics, Precession, Radial polarization, lcsh:QC770-798, Physics - Accelerator Physics, ddc:530, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, business, Storage ring
Abstract

This paper describes a time-marking system that enables a measurement of the in-plane (horizontal) polarization of a 0.97-GeV/c deuteron beam circulating in the Cooler Synchrotron (COSY) at the Forschungszentrum J\"ulich. The clock time of each polarimeter event is used to unfold the 120-kHz spin precession and assign events to bins according to the direction of the horizontal polarization. After accumulation for one or more seconds, the down-up scattering asymmetry can be calculated for each direction and matched to a sinusoidal function whose magnitude is proportional to the horizontal polarization. This requires prior knowledge of the spin tune or polarization precession rate. An initial estimate is refined by re-sorting the events as the spin tune is adjusted across a narrow range and searching for the maximum polarization magnitude. The result is biased toward polarization values that are too large, in part because of statistical fluctuations but also because sinusoidal fits to even random data will produce sizeable magnitudes when the phase is left free to vary. An analysis procedure is described that matches the time dependence of the horizontal polarization to templates based on emittance-driven polarization loss while correcting for the positive bias. This information will be used to study ways to extend the horizontal polarization lifetime by correcting spin tune spread using ring sextupole fields and thereby to support the feasibility of searching for an intrinsic electric dipole moment using polarized beams in a storage ring. This paper is a combined effort of the Storage Ring EDM Collaboration and the JEDI Collaboration., Comment: 28 pages, 15 figures, prepared for Physical Review ST - Accelerators and Beams

Published
2014

35. Better-resolution measurement of vertical scattering angle in a new ion-optical mode of spectrometer 'Grand Raiden'

Author

Hisanori Fujita, Kichiji Hatanaka, Masatoshi Itoh, Yoshitaka Fujita, H. Ueno, E. J. Stephenson, Tetsuo Noro, T. Taki, Keisuke Tamura, H. Sakaguchi, C. C. Foster, and G. P. A. Berg

Subjects
Physics, Nuclear and High Energy Physics, Spectrometer, business.industry, Scattering, Resolution (electron density), Ion, Momentum, Cardinal point, Optics, Vertical direction, business, Instrumentation, Excitation
Abstract

Demand for near-zero-degree measurements using a magnetic spectrometer is increasing with the growing interest in the study of L ¼ 0 nuclear excitation modes. For the precise determination of scattering angles near 08, both horizontal and vertical scattering angle components have to be measured with good accuracy. It is, however, not easy to realize a good vertical angle resolution using modern high-resolution magnetic spectrometers with small vertical angle magnifications, like ‘‘Grand Raiden’’ at RCNP or ‘‘K600’’ at IUCF. A new ion-optical mode which enables the precise determination of vertical components of scattering angles from vertical position measurements in the focal plane has been developed for these spectrometers. For the wide range of spatial as well as momentum acceptances, vertical angle resolution better than 8 mrad is realized for Grand Raiden at RCNP. # 2001 Elsevier Science B.V. All rights reserved.

Published
2001

36. Midrapidity Antiproton-to-Proton Ratio fromAu+AuCollisions atsNN=130GeV

Author

Sergey Voloshin, J. Engelage, K. J. Foley, R. S. Longacre, J. M. Landgraf, M. Strikhanov, N. Xu, C. Roy, J. Sandweiss, G. D. Westfall, J. Baudot, B. Erazmus, J. Castillo, Y. V. Zanevski, Malgorzata Anna Janik, G. Igo, J. Carroll, D. M. Moltz, S. W. Wissink, A. A. Kuznetsov, C. O. Blyth, B. Norman, A. Klyachko, A. Maliszewski, H. M. Spinka, V. M. Leontiev, Olivier Ravel, R. Wells, V. A. Nikitin, K. Turner, T. Ullrich, D.E. Greiner, A. C. Saulys, K. E. Shestermanov, D. Cebra, Y. Fisyak, P. Fachini, A. Ogawa, Ian Johnson, V. S. Shvetcov, C. A. Whitten, Z. Z. Xu, T. J.M. Symons, E. Platner, A. Stolpovsky, H. Hümmler, W. Pinganaud, Jay Roberts, P. Leszczynski, S. Lange, T. Herston, S. J. Lindenbaum, Adam Ryszard Kisiel, P. Seyboth, Lee Stuart Barnby, Yu Melnick, L. Kotchenda, W. Christie, Vladimir Tikhomirov, S. Y. Panitkin, R. Bossingham, M. Lopez-Noriega, H. J. Crawford, J. G. Cramer, C. L. Kunz, B. Choi, A. Szanto de Toledo, C. F. Moore, H. G. Ritter, M. Castro, J. Lamas-Valverde, N. Schmitz, A. I. Kulikov, Matthew J. Anderson, R. Bellwied, A. S. Konstantinov, H. Bichsel, G. Odyniec, V. Trofimov, A. P. Meschanin, K. Krueger, Alexander Kovalenko, L. V. Nogach, R. Witt, E. Yamamoto, J. H. Thomas, L. Conin, G. Skoro, A. A.P. Suaide, Christophe Pierre Suire, Masashi Kaneta, M. Heffner, W. M. Zhang, Andrey Vasiliev, J. C. Dunlop, S. Radomski, S. Trentalange, C. E. Allgower, Zubayer Ahammed, V. Ghazikhanian, M. J. LeVine, A. H. Tang, W. A. Love, Joakim Nystrand, M. Cherney, John Z. H. Zhang, Thomas Michael Cormier, Vladimir Petrov, E. G. Judd, P. Nevski, T. Pawlak, David Lynn, L. Madansky, M. Kramer, G. S. Averichev, S. P. Chernenko, W. J. Llope, T. S. McShane, I. Sakrejda, E. Sugarbaker, A. Cardenas, Janet Elizabeth Seger, H. Z. Huang, D. Russ, Yu Chen, Fuqiang Wang, G. S. Mutchler, C. P. Lansdell, R.J.M. Snellings, J. Porter, L. S. Schroeder, Guy Paic, A. Chikanian, S. S. Shimanskii, J. Mitchell, B. Lasiuk, J. Grabski, A. I. Pavlinov, H. Long, Frank Jm Geurts, M. B. Tonjes, V. Morozov, P. Szarwas, V. I. Yurevich, J. N. Marx, D. Hardtke, F. Laue, R. D. Majka, A. V. Brandin, J. Sowinski, B. K. Srivastava, I. M. Vasilevski, J. Berger, J. Gans, E. Finch, Boris Hippolyte, S. E. Vigdor, V. A. Moiseenko, T. J. Humanic, Christian Claude Kuhn, A. Boucham, Marcelo Gameiro Munhoz, D. J. Prindle, I.A. Savin, N. T. Porile, V. B. Dunin, S. Bekele, E. J. Stephenson, M. A. Lisa, Yu A. Matulenko, M. Horsley, B. Stringfellow, A. Ishihara, R. Willson, D. G. Underwood, A. M. VanderMolen, D. Reichhold, T. J. Hallman, A. M. Poskanzer, A. Vanyashin, M. Tokarev, H. H. Wieman, A. S. Hirsch, P. Kravtsov, C. Adler, C. Struck, J. Takahashi, A. Ridiger, Torre Wenaus, Jeffrey G. Reid, Thomas A. Trainor, Morton Kaplan, R. P. Scharenberg, H. S. Matis, C. A. Ogilvie, W. W. Jacobs, D. Seliverstov, A. Schüttauf, Subhasis Chattopadhyay, Peter Martin Jacobs, S. Heppelmann, S. V. Razin, D. Flierl, H. Ward, M. A. C. Lamont, S. B. Nurushev, Z. Milosevich, L. Martin, G. Van Buren, R. K. Kutuev, J. M. Nelson, H. Stroebele, W. Peryt, J. E. Draper, N.D. Gagunashvili, J. P. Coffin, O. V. Rogachevski, V. Perevoztchikov, Alexander Khodinov, L. C. Bland, S. U. Pandey, A. E. Yakutin, J. W. Harris, E. Gushin, G. J. Kunde, P. Yepes, V. Eckardt, A. Yokosawa, G. Eppley, J. Pluta, Q. Li, Gerald W Hoffmann, Mingshui Chen, Thomas LeCompte, W. S. Deng, S. Margetis, O. A. Grachov, V. Grigoriev, R. L. Ray, E. Potrebenikova, V. V. Belaga, T. Ljubicic, F. Retiere, N. G. Minaev, H. Caines, V. L. Rykov, Peter Graham Jones, L. Didenko, J. Schambach, E. L. Hjort, J. Balewski, M. C. de la Barca Sánchez, A. Lebedev, M. M. de Moura, Marie Germain, Claude Andre Pruneau, Y. Panebratsev, G. Rai, A. N. Zubarev, R. Zoulkarneev, J. Klay, Jinghui Yang, G. LoCurto, S. R. Klein, O. Barannikova, D. L. Olson, M. DeMello, M. Oldenburg, V. Emelianov, A. A. Derevschikov, D. Keane, Nikolai Smirnov, R. Stock, L. G. Efimov, Yu. Ivanshin, B. E. Bonner, O. D. Tsai, and M. I. Ferguson

Subjects
Physics, Range (particle radiation), Particle physics, Proton, General Physics and Astronomy, Baryon, Nuclear physics, Pair production, Antiproton, High Energy Physics::Experiment, Rapidity, Nuclear Experiment, Nucleon, Energy (signal processing)
Abstract

We report results on the ratio of mid-rapidity anti-proton to proton yields in Au+Au collisions at $\rts = 130$ GeV per nucleon pair as measured by the STAR experiment at RHIC. Within the rapidity and transverse momentum range of $|y

Published
2001

37. Elliptic Flow inAu+AuCollisions at√sNN=130GeV

Author

N. Stone, Christophe Pierre Suire, A. Lebedev, B. Miller, M. M. de Moura, M. Dialinas, P. Middlekamp, J. Scheblien, V. Ghazikhanian, A. Etkin, A. H. Tang, A. P. Meschanin, R.Kh. Kutuev, J. Berger, J. L. Romero, V. Fine, J. Engelage, T. J. Humanic, Peter J. Lindstrom, D. Zimmerman, I.A. Savin, N. T. Porile, Yu A. Matulenko, M. Horsley, Thomas LeCompte, B. Stringfellow, J. Sedlmeir, L. Smykov, E. Finch, T. S. McShane, J. W. Harris, Joakim Nystrand, V. B. Dunin, J. Grabski, P. Seyboth, D. Dayton, C. J. Liaw, R. Bossingham, J. N. Marx, C. Drancourt, S. Tonse, W. S. Deng, J. G. Cramer, R. A. Scheetz, A. Stolpovsky, H. Hümmler, L. Kotchenda, G. Koehler, E. Gushin, G. J. Kunde, P. Yepes, V. Eckardt, M. Kramer, A. I. Pavlinov, Y. Panebratsev, D. Grosnick, Granville Ott, G. Eppley, A. V. Brandin, V. Trofimov, J. M. Landgraf, M. Strikhanov, K. Krueger, M. B. Tonjes, E. I. Shakaliev, A. Yokosawa, Jinghui Yang, E. Sugarbaker, J. Hunter, H. Z. Huang, V. Morozov, A. Tarchini, S. V. Razin, K. Wilson, G. Rai, Y. Shi, G. Van Buren, J. M. Nelson, P. A. DeYoung, J. Pluta, C. Roy, H. Stroebele, J. Carroll, C. Byrd, N. Xu, G. D. Westfall, D. Padrazo, R. Wells, C. Struck, W. Pinganaud, D. Hardtke, F. Laue, J.F. Amsbaugh, Jay Roberts, N. Adams, David Fritz, J. Sandweiss, G. LoCurto, A. C. Saulys, S. R. Klein, C. E. Allgower, R. D. Majka, J. Zhu, Sergey Voloshin, J. Sowinski, Matthew Nguyen, W. Peryt, J. Takahashi, J. Wolf, C. Feliciano, Y. Fisyak, L. Greiner, K. J. Foley, J. Schambach, E. L. Hjort, S. Pirogov, A. Ogawa, Ian Johnson, Krista M. Marks, S. E. Vigdor, Vladimir Petrov, C. L. Kunz, Z. Li, O. Barannikova, D. L. Olson, F. P. Brady, Gerald W Hoffmann, S. P. Chernenko, D. Seliverstov, A. Schüttauf, Christian Claude Kuhn, W. J. Llope, Q. Li, C. O. Blyth, C. F. Moore, M. Cherney, H. Fessler, W. Christie, Thomas Michael Cormier, D.E. Greiner, T. Krupien, Torre Wenaus, Masashi Kaneta, Ross Schlueter, W. M. Zhang, Andrey Vasiliev, D. Hill, Richard C. Jared, M. Calderón de la Barca Sánchez, R. Weidenbach, T. Nguyen, A. Cardenas, Peter Martin Jacobs, N. Schmitz, S. Chatopadhyay, P. Nevski, M. Lopez-Noriega, A. Klyachko, R. Witt, E. Yamamoto, J. Klay, Thomas A. Trainor, W. R. Edwards, P. Sappenfield, N.D. Gagunashvili, J. Baudot, E. A. Matyushevski, P. Kuczewski, J. C. Dunlop, A. A. Derevschikov, K. Olchanski, V. I. Danilov, C. P. Lansdell, Wilfred J. Braithwaite, E. Mogavero, R.J.M. Snellings, Janet Elizabeth Seger, J. Lin, M. A. C. Lamont, S. B. Nurushev, Z. Milosevich, B. Lasiuk, J. Wisdom, Y. V. Zanevski, F. Retiere, W. Hunt, V. Kormilitsyne, D. Russ, B. E. Bonner, J. T.M. Chrin, G. S. Mutchler, H. Diaz, J. R. Hall, Zubayer Ahammed, G. A. Ososkov, M. J. LeVine, B. Norman, J. Gross, H. Long, K. Bradley, Yu Chen, Wen-Chang Chen, N. G. Minaev, O. D. Tsai, R. P. Scharenberg, Marie Germain, R. Seymour, M. A. Howe, B. Choi, R. Marstaller, W. Betts, Vladimir Tikhomirov, Salahuddin Ahmad, I. Polk, H. S. Matis, G. C. Harper, A. S. Hirsch, P. Kravtsov, A. Maliszewski, Alexander Kovalenko, L. V. Nogach, L. C. Bland, S. Bennett, H. J. Crawford, I. Vakula, C. Adler, F. S. Bieser, L. Wood, A. N. Zubarev, C. A. Ogilvie, G. Brugalette, V. S. Shvetcov, L. S. Schroeder, J. Meier, H. Liu, S. U. Pandey, A. E. Yakutin, I. Flores, Morton Kaplan, V. Perevotchikov, C. A. Whitten, M. Pentia, Marek Gazdzicki, L. Lakehal-Ayat, D. Lopiano, S. Trentalange, A. Ridiger, W. W. Jacobs, M. I. Ferguson, J. Lamas-Valverde, C. Gojak, M. Botlo, Guy Paic, I. Sakrejda, T. Ngo, E. Platner, B. Minor, V. Lindenstruth, V. A. Nikitin, S. Heppelmann, D. Flierl, Ma Bloomer, John Z. H. Zhang, A. Chikanian, S. S. Shimanskii, J. Mitchell, E. G. Judd, L. Martin, Jeffrey G. Reid, B. K. Srivastava, I. M. Vasilevski, K. E. Shestermanov, V. V. Belaga, Lincoln D. Carr, J. Gans, S. Lange, L. Arnold, Boris Hippolyte, G. Skoro, M. Heffner, J. E. Draper, J. Puskar-Pasewicz, R. Morse, V. Grigoriev, J. P. Coffin, O. V. Rogachevski, N. Bouillo, M. DeMello, S. J. Lindenbaum, N. Mikhalin, A. Boucham, H. Ward, M. Oldenburg, Peter Graham Jones, R. L. Ray, V. Emelianov, D. Keane, A. R. Baldwin, A. A. P. Suaide, L. Didenko, Damien Bonnet, Nikolai Smirnov, R. Stock, S. Y. Panitkin, E. Potrebenikova, W. J. Leonhardt, S. Bekele, S. Bouvier, V. P. Kenney, L. G. Efimov, Frank Jm Geurts, Yu. Ivanshin, J. Castillo, S. W. Wissink, R. L. Brown, W. Dominik, P. Jensen, A. Ishihara, T. Ljubicic, Alexander Khodinov, Robert Stone, M. Tokarev, G. Guilloux, Robert R. J. Maier, D. DiMassimo, E. Anderssen, A. M. VanderMolen, H. H. Wieman, H. Caines, S. Jacobson, D. Shuman, R. Willson, D. G. Underwood, J. Wirth, D. Reichhold, T. J. Hallman, T. J. M. Symons, K. Turner, A. Szanto de Toledo, A. M. Poskanzer, J. Tarzian, P. He, K. Solberg, T. Pawlak, A. Vanyashin, Z. Sandler, B. Caylor, R. S. Longacre, V. L. Rykov, J. Porter, G. Igo, J. Seyboth, P. Fachini, D. D. Weerasundara, Mingshui Chen, M. Grau, S. Margetis, O. A. Grachov, M. Schulz, J. R. Lutz, Rainer Arno Ernst Renfordt, J. Balewski, H. G. Ritter, Claude Andre Pruneau, H. Arnesen, R. Zoulkarneev, R. Bellwied, A. S. Konstantinov, K. H. Ackermann, D. M. Moltz, A. A. Kuznetsov, Ivan Kotov, T. Noggle, V. M. Leontiev, Olivier Ravel, J. Whitfield, T. Ullrich, D. Roehrich, B. Erazmus, Z. Z. Xu, D. Cebra, C. Consiglio, M. Beddo, Yu Melnick, P. Leszczynski, J. Bercovitz, T. Herston, J. Riso, Lee Stuart Barnby, V. A. Moiseenko, Marcelo Gameiro Munhoz, D. J. Prindle, E. J. Stephenson, M. A. Lisa, W. A. Love, T. Nussbaum, Daniel Ferenc, Fuqiang Wang, H. Bichsel, G. Odyniec, V. I. Yurevich, E. S. Braithwaite, J. Boehm, T. Eggert, David Lynn, L. Madansky, R. Sanchez, J. Dioguardi, J. H. Thomas, L. Conin, G. Visser, G. S. Averichev, C. P. McParland, H. M. Spinka, J. Rasson, Chinh Vu, and Matthew J. Anderson

Subjects
Physics, Particle physics, Time projection chamber, Hadron, Elliptic flow, General Physics and Astronomy, Observable, Particle accelerator, Charged particle, law.invention, Nuclear physics, law, Pseudorapidity, Nuclear Experiment, Relativistic Heavy Ion Collider
Abstract

Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at √(sNN) = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v₂, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

Published
2001

38. Development of a tagged neutron facility for neutron scattering experiments at intermediate energies

Author

Todd E. Peterson, W. W. Jacobs, Nils Olsson, S. W. Wissink, Yaoqi Zhou, L. C. Bland, Leif Nilsson, P. Nadel-Turonski, J. Rapaport, A. Klyachko, T. Rinckel, T. Kinashi, E. J. Stephenson, S. E. Vigdor, and Jan Blomgren

Subjects
Physics, Nuclear and High Energy Physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Neutron scattering, Neutron temperature, Neutron time-of-flight scattering, Nuclear physics, Neutron generator, Neutron cross section, Physics::Accelerator Physics, Neutron source, Neutron detection, Neutron, Atomic physics, Nuclear Experiment
Abstract

We describe the ongoing development of a tagged neutron facility at the Indiana University Cooler. The neutrons are produced via the interaction of a stored 200 MeV proton beam with a deuterium gas jet target. Energy and position measurements of the two l

Published
2000

40. Spin Transfer inppElastic Scattering at 198 MeV: Implications for theπNNCoupling Constant

Author

T. Black, S. M. Bowyer, S. W. Wissink, S.P. Wells, A. D. Bacher, E. J. Stephenson, W. M. Schmitt, Seonho Choi, A.C. Betker, K. Jiang, J. Sowinski, T.W. Bowyer, C. Yu, and W. A. Franklin

Subjects
Physics, Elastic scattering, Coupling constant, Particle physics, Pion, law, Cyclotron, General Physics and Astronomy, Spin transfer, Sensitivity (control systems), Coupling (probability), law.invention
Abstract

A precision measurement of spin transfer in $\mathrm{pp}$ elastic scattering at 197.8 MeV has been completed recently at the Indiana University Cyclotron Facility. The new data span a kinematic regime chosen specifically to maximize sensitivity to the neutral $\ensuremath{\pi}\mathrm{NN}$ coupling constant. Our results provide strong support for modern potential models of the $\mathrm{NN}$ interaction in which a relatively weak pion coupling ( ${g}_{0}^{2}\ensuremath{\approx}13.6$, ${f}_{0}^{2}\ensuremath{\approx}0.075$) is employed, but disagree significantly with predictions of older models in which ${g}_{0}^{2}\ensuremath{\approx}14.4$. Calculations in a one-boson-exchange framework indicate that most of these latter differences can be removed by reducing ${g}_{0}^{2}$ from 14.4 to 13.6 in these models.

Published
1999

41. Tz = −1 nuclei in the rp-process — astrophysical implications and a new experimental approach

Author

T. Black, K. Jiang, P. Tischhauser, E. J. Stephenson, Seonho Choi, B. Lozowski, G.P.A. Berg, Hendrik Schatz, Joachim Görres, A. D. Bacher, Edward Stech, C. C. Foster, and Michael Wiescher

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Flow (mathematics), Pulsar, Proton, Astrophysics::High Energy Astrophysical Phenomena, Measure (physics), Astrophysics, rp-process, Nuclear Experiment
Abstract

The ( α , 8 He) reaction is used to measure level energies in very proton rich nuclei. The results allow a more reliable calculation of the reaction flow in the rp and αp processes in Novae, X-ray pulsars and X-ray bursts.

Published
1999

42. Possible observation of the orbital in 96249Cm

Author

John P. Greene, G.P.A. Berg, B. B. Back, W.R. Lozowski, T. Yamanaka, L. R. Morss, C. C. Foster, A. D. Bacher, W. M. Schmitt, E. J. Stephenson, T. Ishii, I. Ahmad, and R. R. Chasman

Subjects
Physics, Momentum, Nuclear and High Energy Physics, Angular momentum, Spectrometer, law, Cyclotron, Alpha particle, Atomic physics, Excitation, Spectral line, Ion, law.invention
Abstract

The position of the K 17 2 shell orbital plays a significant role in determining the shell correction energy and hence the stability of the superheavy elements. A deformed component of this orbital, 1 2 + [880] , comes down in energy with increasing prolate deformation, and is expected to have an excitation energy of less than 2 MeV in nuclei with N = 153. We have performed the reaction 248Cm(4He,3He) using 98.5-MeV alpha particles from the IUCF cyclotron to populate high-l states in 249Cm. this reaction preferentially excites high-l states because of the angular momentum mismatch. The emerging 3He ions were momentum analyzed with the K600 magnetic spectrometer. Spectra were measured at θcm = 4.1°, 6.1°, 10.2°, 12.2°, and 16.2° The spectrometer was calibrated with the 208Pb(4He,3He) and 232Th(4He,3He) reactions at the same incident energy. Three strong peaks were identified in the 248Cm(4He,3He) spectrum and these have been given tentative assignments: 593 keV, 15 2 11 2 − [725] ; 1560 keV and 1898 keV, 17 2 1 2 + [880] , 15 2 13 2 − [716] . Our data do not distinguish between the 17 2 + and 15 2 − assignments.

Published
1999

43. Neutron transition densities for low lying states in58Niobtained by using 200 MeV inelastic proton scattering

Author

S. W. Wissink, S. Chang, S. M. Bowyer, E. J. Stephenson, S.P. Wells, G.P.A. Berg, Jianglai Liu, C. Olmer, J. Lisantti, A. D. Bacher, and K. Hicks

Subjects
Physics, Nuclear and High Energy Physics, Quasielastic scattering, X-ray Raman scattering, Quasielastic neutron scattering, Neutron, Inelastic scattering, Neutron scattering, Atomic physics, Small-angle neutron scattering, Inelastic neutron scattering
Published
1998

44. Analyzing powers and cross sections ofp→p→pnπ+near threshold

Author

W. W. Jacobs, P. V. Pancella, W. K. Brooks, R. W. Flammang, W. W. Daehnick, R. A. Thompson, J. G. Hardie, T. Rinckel, D. J. Tedeschi, E. J. Stephenson, C. C. Foster, S. A. Dytman, and T. Vrana

Subjects
Nuclear physics, Momentum, Physics, Nuclear and High Energy Physics, Cross section (physics), Near threshold, Pion, Order (ring theory), Atomic physics, Resonance (particle physics), Beam (structure)
Abstract

Analyzing powers for {rvec p}p{r_arrow}pn{pi}{sup +} were measured for the first time close to threshold at beam energies that yield maximum pion momentum fractions ({eta}{equivalent_to}p{sub c.m.}{sup max}/m{sub {pi}}c) of {eta}=0.22, 0.42, and 0.50, and enable a decomposition of the low order partial waves. Cross sections were measured at seven different beam energies with {eta}=0.07, 0.17, 0.22, 0.28, 0.34, 0.42, and 0.50. The analysis shows that pion s-wave channels dominate the reaction. The p-wave channel containing the {Delta} resonance contributes, at {eta}=0.22, less than one-tenth of the total cross section and less than one-third of the total cross section at {eta}=0.42 and 0.50. The nonresonant p-wave channel contributes less than 1{percent} of the cross section at these three energies. {copyright} {ital 1998} {ital The American Physical Society}

Published
1998

46. Analyzing powers in and determination of pion S and P wave amplitudes near threshold

Author

W. W. Jacobs, J. G. Hardie, W. W. Daehnick, D. J. Tedeschi, P. V. Pancella, C. C. Foster, R. W. Flammang, T. Rinckel, S. A. Dytman, T. Vrana, E. J. Stephenson, W. K. Brooks, and R. A. Thompson

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Cross section (physics), Near threshold, Pion, Amplitude, Partial wave analysis, P wave
Abstract

Analyzing powers were measured and used to quantify the observation that s-wave processes dominate near threshold. Values of Ay(θπ,φπ=0°) are presented for η values of 0.22, 0.42 and 0.50. Maximum analyzing powers AN0 are equal to −0.13, −0.24, and −0.28, respectively. A partial wave analysis, made possible by the new analyzing powers and available cross sections, indicates that the s-wave contribution to the cross section constitutes about 91% of the total cross section at η=0.22, or 300 MeV. It decreases to about 75% for η=0.5.

Published
1998

47. Calibration of a neutron polarimeter to measure the electric form factor of the neutron

Author

G. Niculescu, C. C. Foster, C. Halli, J.E. Anderson, C. R. Howell, D. Keane, J. W. Watson, J. M. Cameron, David Manley, T. Eden, A. R. Baldwin, R. Suleiman, M. Olson, A. Lai, Richard Madey, C. C. Chang, W.-M. Zhang, Oliver Keith Baker, B. D. Anderson, Pete Markowitz, E. J. Stephenson, R. L. Walter, M. Elaasar, I. Niculescu, M.M. Niboh, H. Liu, James J. Kelly, and W.R. Brown

Subjects
Physics, Nuclear and High Energy Physics, Proton, Cyclotron, Electric form factor, Particle accelerator, Polarimeter, law.invention, Nuclear physics, Nuclear Energy and Engineering, law, Electromagnetic shielding, Neutron, Electrical and Electronic Engineering, Beam (structure)
Abstract

We measured the analyzing power and the efficiency of a new neutron polarimeter that was designed to measure G/sub E//sup n/, the neutron electric form factor. The polarimeter calibration was performed as experiment E377 at the Indiana University Cyclotron Facility (IUCF) with the /sup 14/C(p/spl I.oarr/,n/spl I.oarr/)/sup 14/N reaction at proton beam energies of 124.0, 164.6, and 199.7 MeV without any shielding material ahead of the polarimeter; in addition, at 164.6 MeV we measured the analyzing power with 10 cm of lead, sandwiched between 3.5-cm iron plates, ahead of the polarimeter.

Published
1998

48. First Measurement of Excited States in the Very Proton Rich Nucleus24Si and the Consequences for22Na Nucleosynthesis in Novae

Author

G. P. A. Berg, E. J. Stephenson, T. Black, A.D. Bacher, Edward Stech, Joachim Görres, K. Jiang, H. Herndl, Seonho Choi, N. Kaloskamis, P. Tischhauser, C. C. Foster, Hendrik Schatz, and Michael Wiescher

Subjects
Physics, medicine.anatomical_structure, Proton, Nucleosynthesis, Excited state, medicine, General Physics and Astronomy, Production (computer science), Atomic physics, Nucleus, Energy (signal processing), Excitation
Abstract

The ${}^{28}\mathrm{Si}(\ensuremath{\alpha}{,}^{8}\mathrm{He}{)}^{24}\mathrm{Si}$ reaction has been used to measure the energies of the first two excited states in ${}^{24}$Si. The excitation energies were found to be $1.879\ifmmode\pm\else\textpm\fi{}0.011$ and $3.441\ifmmode\pm\else\textpm\fi{}0.010\mathrm{MeV}$. These data allow for the first time the calculation of the stellar reaction rate of ${}^{23}\mathrm{Al}(p,\ensuremath{\gamma}{)}^{24}\mathrm{Si}$ on the basis of experimental information. This reaction is of considerable interest, since it might lead to a decrease of the ${}^{22}$Na production in nova explosions, and solve the discrepancy between the ${}^{22}$Na yield predictions of nova models and recent COMPTEL observations. We show, however, that the temperatures and densities required for a significantly reduced ${}^{22}$Na yield are not reached in current nova models.

Published
1997

49. Evidence for the Isoscalar Giant Dipole Resonance in208PbUsing InelasticαScattering at and near 0°

Author

G.P.A. Berg, W. Reviol, M.N. Harakeh, D.A. Roberts, J. Lisantti, C. C. Foster, J. W. Jänecke, B.F. Davis, K. Pham, M. Fujiwara, Yan Alexander Wang, Hidetoshi Akimune, A. D. Bacher, U. Garg, and E. J. Stephenson

Subjects
Physics, Nuclear physics, Dipole, Scattering, Giant resonance, Isoscalar, Nuclear Theory, General Physics and Astronomy, Resonance, Alpha particle, Atomic physics, Inelastic scattering, Charged particle
Abstract

The isoscalar giant dipole resonance (ISGDR) in ${}^{208}\mathrm{Pb}$ has been investigated using inelastic scattering of 200 MeV $\ensuremath{\alpha}$ particles at and near 0\ifmmode^\circ\else\textdegree\fi{} where the angular distribution of the ISGDR can be clearly differentiated from those of other modes. The ``difference of spectra'' technique was employed to separate the ISGDR from the high-energy octupole resonance (HEOR). These data provide the clearest evidence yet for the ISGDR adjacent to the HEOR. With these results, all expected isoscalar $\ensuremath{\lambda}\ensuremath{\le}3$ resonances in ${}^{208}\mathrm{Pb}$ have been identified.

Published
1997

50. Effective IsovectorNNInteraction Strengths Determined from theS28i(p→,p→′)S28i(6−,T=1)Reaction

Author

C. Olmer, A. D. Bacher, J. Lisantti, S. M. Bowyer, S. W. Wissink, Jianglai Liu, S. Chang, E. J. Stephenson, and S.P. Wells

Subjects
Physics, symbols.namesake, Pauli exclusion principle, Mean field theory, Transition strength, symbols, General Physics and Astronomy, Inelastic electron scattering, Sigma, Spin-flip, Atomic physics, Polarization (waves), Excitation
Abstract

We report measurements of {sigma}({theta}), A({theta}), and polarization transfer for the {sup 28}Si({rvec p},{rvec p}{sup {prime}}){sup 28}Si reaction to the 6{sup {minus}},T=1 state at 14.36MeV initiated with 198MeV polarized protons. Normalization of the transition strength in the distorted-wave impulse approximation (DWIA) to inelastic electron scattering overpredicts the spin-longitudinal cross section by more than a factor of 2, while the spin-transverse cross section is nearly correct and the spin-orbit cross section is underpredicted. A reduced in-medium {rho}-meson mass reproduces some of these features, while strong relativistic mean field or Pauli blocking effects are too small. {copyright} {ital 1997} {ital The American Physical Society}

Published
1997

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