355 results on '"W. A. Zajc"'
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302. Systematics of midrapidity transverse energy distributions in limited apertures fromp+Beto Au+Au collisions at relativistic energies
- Author
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P. D. Bond, B. Cole, J. Engelage, R. J. Ledoux, H. E. Wegner, M. J. Tannenbaum, B. Moskowitz, L. P. Remsberg, J. Kang, Ryugo S. Hayano, J. H. Thomas, Hiroyoshi Sakurai, T. Sung, Kenta Shigaki, Yuichi Ikeda, C. Y. Chi, H. J. Crawford, V. Cianciolo, Fuqiang Wang, K. Kimura, R. A. Soltz, M. Vient, D. P. Morrison, David E. Alburger, W. A. Watson, Shinichi Hayashi, M. Gonin, S. Gushue, M. J. LeVine, K. Kurita, Lee Grodzins, E. Duek, C. Chasman, H. C. Britt, O. Vossnack, T. C. Sangster, F. Videbæk, M. Tanaka, S. Y. Fung, P. Stankus, Yasuo Miake, M. A. Bloomer, S. Katcoff, R. J. Morse, S. Tonse, M. Sarabura, L. Birstein, J.W. Olness, E. Vulgaris, George Stephans, M. Torikoshi, I. Juricic, S. Ueno-Hayashi, K. Yagi, M. N. Namboodiri, R. Seto, O. Hansen, J. B. Costales, S. Homma, T. Abbott, P. Vincent, A. Shor, Y. D. Wu, W. A. Zajc, V. Vutsadakis, Y. Akiba, Daniel S. Zachary, Hideki Hamagaki, J. B. Cumming, K. Kitamura, B. Budick, H. Kaneko, H. Z. Huang, W. L. Kehoe, C. G. Parsons, P. Rothschild, D. S. Woodruff, L. Ahle, R. R. Debbe, S. B. Kaufman, S. G. Steadman, S. Nagamiya, T. K. Nayak, Y. Wang, Y. Y. Chu, Z. Chen, J. H. van Dijk, Toru Sugitate, D. R. Beavis, and X. Yang
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,Meson production ,Transverse plane ,Electromagnetic calorimeter ,Distribution (mathematics) ,Pseudorapidity ,High Energy Physics::Experiment ,Production (computer science) ,Atomic physics ,Nuclear Experiment ,Centrality ,Energy (signal processing) - Abstract
Measurements of the A dependence and pseudorapidity interval $(\ensuremath{\delta}\ensuremath{\eta})$ dependence of midrapidity ${E}_{T}$ distributions in a half-azimuth (\ensuremath{\Delta}\ensuremath{\varphi}=\ensuremath{\pi}) electromagnetic calorimeter are presented for $p+\mathrm{Be},$ $p+\mathrm{Au},$ O+Cu, Si+Au, and Au+Au collisions at the BNL-AGS (Alternating-Gradient Synchrotron). The shapes of the upper edges of midrapidity ${E}_{T}$ distributions as a function of the pseudorapidity interval \ensuremath{\delta}\ensuremath{\eta} in the range 0.3 to 1.3, roughly centered at midrapidity, are observed to vary with \ensuremath{\delta}\ensuremath{\eta}, like multiplicity---the upper edges of the distributions flatten as \ensuremath{\delta}\ensuremath{\eta} is reduced. At the typical fixed upper percentiles of ${E}_{T}$ distributions used for nuclear geometry characterization by centrality definition---7 percentile, 4 percentile, 2 percentile, 1 percentile, 0.5 percentile---the effect of this variation in shape on the measured projectile ${A}_{p}$ dependence for ${}^{16}\mathrm{O},$ ${}^{28}\mathrm{Si},$ ${}^{197}$Au projectiles on an Au target is small for the ranges of \ensuremath{\delta}\ensuremath{\eta} and percentile examined. The ${E}_{T}$ distributions for $p+\mathrm{Au}$ and $p+\mathrm{Be}$ change in shape with \ensuremath{\delta}\ensuremath{\eta}; but in each \ensuremath{\delta}\ensuremath{\eta} interval the shapes of the $p+\mathrm{Au}$ and $p+\mathrm{Be}$ distributions remain indentical with each other---a striking confirmation of the absence of multiple-collision effects at midrapidity at AGS energies. The validity of the nuclear geometry characterization versus \ensuremath{\delta}\ensuremath{\eta} is illustrated by plots of the ${E}_{T}(\ensuremath{\delta}\ensuremath{\eta})$ distribution in each \ensuremath{\delta}\ensuremath{\eta} interval in units of the measured $〈{E}_{T}(\ensuremath{\delta}\ensuremath{\eta}){〉}_{p+\mathrm{Au}}$ in the same \ensuremath{\delta}\ensuremath{\eta} interval for $p+\mathrm{Au}$ collisions. These plots, in the physically meaningful units of ``number of average $p+\mathrm{Au}$ collisions,'' are nearly universal as a function of \ensuremath{\delta}\ensuremath{\eta}, confirming that the reaction dynamics for ${E}_{T}$ production at midrapidity at AGS energies is governed by the number of projectile participants and can be well characterized by measurements in apertures as small as \ensuremath{\Delta}\ensuremath{\varphi}=\ensuremath{\pi}, \ensuremath{\delta}\ensuremath{\eta}=0.3.
- Published
- 2001
303. Measurement of the midrapidity transverse energy distribution from square root of [(s)NN] = 130 GeV Au + Au collisions at RHIC
- Author
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K, Adcox, S S, Adler, N N, Ajitanand, Y, Akiba, J, Alexander, L, Aphecetche, Y, Arai, S H, Aronson, R, Averbeck, T C, Awes, K N, Barish, P D, Barnes, J, Barrette, B, Bassalleck, S, Bathe, V, Baublis, A, Bazilevsky, S, Belikov, F G, Bellaiche, S T, Belyaev, M J, Bennett, Y, Berdnikov, S, Botelho, M L, Brooks, D S, Brown, N, Bruner, D, Bucher, H, Buesching, V, Bumazhnov, G, Bunce, J, Burward-Hoy, S, Butsyk, T A, Carey, P, Chand, J, Chang, W C, Chang, L L, Chavez, S, Chernichenko, C Y, Chi, J, Chiba, M, Chiu, R K, Choudhury, T, Christ, T, Chujo, M S, Chung, P, Chung, V, Cianciolo, B A, Cole, D G, D'Enterria, G, David, H, Delagrange, A, Denisov, A, Deshpande, E J, Desmond, O, Dietzsch, B V, Dinesh, A, Drees, A, Durum, D, Dutta, K, Ebisu, Y V, Efremenko, K, El Chenawi, H, En'yo, S, Esumi, L, Ewell, T, Ferdousi, D E, Fields, S L, Fokin, Z, Fraenkel, A, Franz, A D, Frawley, S Y, Fung, S, Garpman, T K, Ghosh, A, Glenn, A L, Godoi, Y, Goto, S V, Greene, M, Grosse Perdekamp, S K, Gupta, W, Guryn, H A, Gustafsson, J S, Haggerty, H, Hamagaki, A G, Hansen, H, Hara, E P, Hartouni, R, Hayano, N, Hayashi, X, He, T K, Hemmick, J M, Heuser, M, Hibino, J C, Hill, D S, Ho, K, Homma, B, Hong, A, Hoover, T, Ichihara, K, Imai, M S, Ippolitov, M, Ishihara, B V, Jacak, W Y, Jang, J, Jia, B M, Johnson, S C, Johnson, K S, Joo, S, Kametani, J H, Kang, M, Kann, S S, Kapoor, S, Kelly, B, Khachaturov, A, Khanzadeev, J, Kikuchi, D J, Kim, H J, Kim, S Y, Kim, Y G, Kim, W W, Kinnison, E, Kistenev, A, Kiyomichi, C, Klein-Boesing, S, Klinksiek, L, Kochenda, D, Kochetkov, V, Kochetkov, D, Koehler, T, Kohama, A, Kozlov, P J, Kroon, K, Kurita, M J, Kweon, Y, Kwon, G S, Kyle, R, Lacey, J G, Lajoie, J, Lauret, A, Lebedev, D M, Lee, M J, Leitch, X H, Li, Z, Li, D J, Lim, M X, Liu, X, Liu, Z, Liu, C F, Maguire, J, Mahon, Y I, Makdisi, V I, Manko, Y, Mao, S K, Mark, S, Markacs, G, Martinez, M D, Marx, A, Masaike, F, Matathias, T, Matsumoto, P L, McGaughey, E, Melnikov, M, Merschmeyer, F, Messer, M, Messer, Y, Miake, T E, Miller, A, Milov, S, Mioduszewski, R E, Mischke, G C, Mishra, J T, Mitchell, A K, Mohanty, D P, Morrison, J M, Moss, F, Mühlbacher, M, Muniruzzaman, J, Murata, S, Nagamiya, Y, Nagasaka, J L, Nagle, Y, Nakada, B K, Nandi, J, Newby, L, Nikkinen, P, Nilsson, S, Nishimura, A S, Nyanin, J, Nystrand, E, O'Brien, C A, Ogilvie, H, Ohnishi, I D, Ojha, M, Ono, V, Onuchin, A, Oskarsson, L, Osterman, I, Otterlund, K, Oyama, L, Paffrath, A P, Palounek, V S, Pantuev, V, Papavassiliou, S F, Pate, T, Peitzmann, A N, Petridis, C, Pinkenburg, R P, Pisani, P, Pitukhin, F, Plasil, M, Pollack, K, Pope, M L, Purschke, I, Ravinovich, K F, Read, K, Reygers, V, Riabov, Y, Riabov, M, Rosati, A A, Rose, S S, Ryu, N, Saito, A, Sakaguchi, T, Sakaguchi, H, Sako, T, Sakuma, V, Samsonov, T C, Sangster, R, Santo, H D, Sato, S, Sato, S, Sawada, B R, Schlei, Y, Schutz, V, Semenov, R, Seto, T K, Shea, I, Shein, T A, Shibata, K, Shigaki, T, Shiina, Y H, Shin, I G, Sibiriak, D, Silvermyr, K S, Sim, J, Simon-Gillo, C P, Singh, V, Singh, M, Sivertz, A, Soldatov, R A, Soltz, S, Sorensen, P W, Stankus, N, Starinsky, P, Steinberg, E, Stenlund, A, Ster, S P, Stoll, M, Sugioka, T, Sugitate, J P, Sullivan, Y, Sumi, Z, Sun, M, Suzuki, E M, Takagui, A, Taketani, M, Tamai, K H, Tanaka, Y, Tanaka, E, Taniguchi, M J, Tannenbaum, J, Thomas, J H, Thomas, T L, Thomas, W, Tian, J, Tojo, H, Torii, R S, Towell, I, Tserruya, H, Tsuruoka, A A, Tsvetkov, S K, Tuli, H, Tydesjö, N, Tyurin, T, Ushiroda, H W, van Hecke, C, Velissaris, J, Velkovska, M, Velkovsky, A A, Vinogradov, M A, Volkov, A, Vorobyov, E, Vznuzdaev, H, Wang, Y, Watanabe, S N, White, C, Witzig, F K, Wohn, C L, Woody, W, Xie, K, Yagi, S, Yokkaichi, G R, Young, I E, Yushmanov, W A, Zajc, Z, Zhang, and S, Zhou
- Abstract
The first measurement of energy produced transverse to the beam direction at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is presented. The midrapidity transverse energy density per participating nucleon rises steadily with the number of participants, closely paralleling the rise in charged-particle density, such thatE(T)/N(ch)remains relatively constant as a function of centrality. The energy density calculated via Bjorken's prescription for the 2% most central Au+Au collisions at square root[s(NN)] = 130 GeV is at least epsilon(Bj) = 4.6 GeV/fm(3), which is a factor of 1.6 larger than found at sqrt[s(NN)] = 17.2 GeV ( Pb+Pb at CERN).
- Published
- 2001
304. Centrality dependence of charged particle multiplicity in Au-Au collisions at square root of (s)NN = 130 GeV
- Author
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K, Adcox, S S, Adler, N N, Ajitanand, Y, Akiba, J, Alexander, L, Aphecetche, Y, Arai, S H, Aronson, R, Averbeck, T C, Awes, K N, Barish, P D, Barnes, J, Barrette, B, Bassalleck, S, Bathe, V, Baublis, A, Bazilevsky, S, Belikov, F G, Bellaiche, S T, Belyaev, M J, Bennett, Y, Berdnikov, S, Botelho, M L, Brooks, D S, Brown, N, Bruner, D, Bucher, H, Buesching, V, Bumazhnov, G, Bunce, J, Burward-Hoy, S, Butsyk, T A, Carey, P, Chand, J, Chang, W C, Chang, L L, Chavez, S, Chernichenko, C Y, Chi, J, Chiba, M, Chiu, R K, Choudhury, T, Christ, T, Chujo, M S, Chung, P, Chung, V, Cianciolo, B A, Cole, D G, D'Enterria, G, David, H, Delagrange, A, Denisov, A, Deshpande, E J, Desmond, O, Dietzsch, B V, Dinesh, A, Drees, A, Durum, D, Dutta, K, Ebisu, Y V, Efremenko, K, El Chenawi, H, En'yo, S, Esumi, L, Ewell, T, Ferdousi, D E, Fields, S L, Fokin, Z, Fraenkel, A, Franz, A D, Frawley, S Y, Fung, S, Garpman, T K, Ghosh, A, Glenn, A L, Godoi, Y, Goto, S V, Greene, M, Grosse Perdekamp, S K, Gupta, W, Guryn, H A, Gustafsson, J S, Haggerty, H, Hamagaki, A G, Hansen, H, Hara, E P, Hartouni, R, Hayano, N, Hayashi, X, He, T K, Hemmick, J, Heuser, M, Hibino, J C, Hill, D S, Ho, K, Homma, B, Hong, A, Hoover, T, Ichihara, K, Imai, M S, Ippolitov, M, Ishihara, B V, Jacak, W Y, Jang, J, Jia, B M, Johnson, S C, Johnson, K S, Joo, S, Kametani, J H, Kang, M, Kann, S S, Kapoor, S, Kelly, B, Khachaturov, A, Khanzadeev, J, Kikuchi, D J, Kim, H J, Kim, S Y, Kim, Y G, Kim, W W, Kinnison, E, Kistenev, A, Kiyomichi, C, Klein-Boesing, S, Klinksiek, L, Kochenda, D, Kochetkov, V, Kochetkov, D, Koehler, T, Kohama, A, Kozlov, P J, Kroon, K, Kurita, M J, Kweon, Y, Kwon, G S, Kyle, R, Lacey, J G, Lajoie, J, Lauret, A, Lebedev, D M, Lee, M J, Leitch, X H, Li, Z, Li, D J, Lim, M X, Liu, X, Liu, Z, Liu, C F, Maguire, J, Mahon, Y I, Makdisi, V I, Manko, Y, Mao, S K, Mark, S, Markacs, G, Martinez, M D, Marx, A, Masaike, F, Matathias, T, Matsumoto, P L, McGaughey, E, Melnikov, M, Merschmeyer, F, Messer, M, Messer, Y, Miake, T E, Miller, A, Milov, S, Mioduszewski, R E, Mischke, G C, Mishra, J T, Mitchell, A K, Mohanty, D P, Morrison, J M, Moss, F, Mühlbacher, M, Muniruzzaman, J, Murata, S, Nagamiya, Y, Nagasaka, J L, Nagle, Y, Nakada, B K, Nandi, J, Newby, L, Nikkinen, P, Nilsson, S, Nishimura, A S, Nyanin, J, Nystrand, E, O'Brien, C A, Ogilvie, H, Ohnishi, I D, Ojha, M, Ono, V, Onuchin, A, Oskarsson, L, Osterman, I, Otterlund, K, Oyama, L, Paffrath, A P, Palounek, V S, Pantuev, V, Papavassiliou, S F, Pate, T, Peitzmann, A N, Petridis, C, Pinkenburg, R P, Pisani, P, Pitukhin, F, Plasil, M, Pollack, K, Pope, M L, Purschke, I, Ravinovich, K F, Read, K, Reygers, V, Riabov, Y, Riabov, M, Rosati, A A, Rose, S S, Ryu, N, Saito, A, Sakaguchi, T, Sakaguchi, H, Sako, T, Sakuma, V, Samsonov, T C, Sangster, R, Santo, H D, Sato, S, Sato, S, Sawada, B R, Schlei, Y, Schutz, V, Semenov, R, Seto, T K, Shea, I, Shein, T A, Shibata, K, Shigaki, T, Shiina, Y H, Shin, I G, Sibiriak, D, Silvermyr, K S, Sim, J, Simon-Gillo, C P, Singh, V, Singh, M, Sivertz, A, Soldatov, R A, Soltz, S, Sorensen, P W, Stankus, N, Starinsky, P, Steinberg, E, Stenlund, A, Ster, S P, Stoll, M, Sugioka, T, Sugitate, J P, Sullivan, Y, Sumi, Z, Sun, M, Suzuki, E M, Takagui, A, Taketani, M, Tamai, K H, Tanaka, Y, Tanaka, E, Taniguchi, M J, Tannenbaum, J, Thomas, J H, Thomas, T L, Thomas, W, Tian, J, Tojo, H, Torii, R S, Towell, I, Tserruya, H, Tsuruoka, A A, Tsvetkov, S K, Tuli, H, Tydesjö, N, Tyurin, T, Ushiroda, H W, van Hecke, C, Velissaris, J, Velkovska, M, Velkovsky, A A, Vinogradov, M A, Volkov, A, Vorobyov, E, Vznuzdaev, H, Wang, Y, Watanabe, S N, White, C, Witzig, F K, Wohn, C L, Woody, W, Xie, K, Yagi, S, Yokkaichi, G R, Young, I E, Yushmanov, W A, Zajc, Z, Zhang, and S, Zhou
- Abstract
We present results for the charged-particle multiplicity distribution at midrapidity in Au-Au collisions at square root of [s(NN)] = 130 GeV measured with the PHENIX detector at RHIC. For the 5% most central collisions we find dN(ch)/d eta(vertical line eta = 0) = 622+/-1(stat)+/-41(syst). The results, analyzed as a function of centrality, show a steady rise of the particle density per participating nucleon with centrality.
- Published
- 2000
305. Proton and deuteron production in Au+Au reactions at11.6A GeV/c
- Author
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Alice Mignerey, H. B. Yao, H. Sako, J. C. Dunlop, V. Cianciolo, Fuqiang Wang, C. Muentz, F. Zhu, T. C. Sangster, W. Eldredge, L. P. Remsberg, J. Luke, J. H. Kang, M. Moulson, K. Kurita, M. D. Baker, G. Heintzelman, K. Yagi, J. B. Cumming, M. N. Namboodiri, M. J. Tannenbaum, Z. Chen, W. A. Zajc, F. Videbæk, J. Chang, A. Kumagai, S. Ueno-Hayashi, Luisa F. Hansen, H. Xiang, C. Chasman, George Stephans, H. J. Crawford, Y. Akiba, R. Seto, E.-J. Kim, Ryugo S. Hayano, Kenta Shigaki, C. Y. Chi, C. A. Ogilvie, H. C. Britt, Yasuo Miake, S. Nagamiya, Y. D. Wu, J. Engelage, Hideki Hamagaki, E. G. Judd, S. Y. Fung, J. Shea, E. Garcia, R. R. Debbe, S. G. Steadman, G. H. Xu, Jongmin Lee, L. Ahle, J. H. Thomas, Y. Y. Chu, J.W. Olness, R. A. Soltz, S. Gushue, Brian Cole, B. Moskowitz, K. Ashktorab, and D. R. Beavis
- Subjects
Coalescence (physics) ,Physics ,Nuclear and High Energy Physics ,Proton ,Nuclear Theory ,Spectral line ,Exponential function ,Nuclear physics ,Transverse plane ,Deuterium ,Transverse mass ,Rapidity ,Atomic physics ,Nuclear Experiment - Abstract
Proton and deuteron distributions from 11.6A GeV/c Au + Au collisions measured by the E802 Collaboration in experiment E-866 are presented. The invariant yield of protons and deuterons is studied as a function of the transverse mass for different cuts of rapidity and centrality. At low mt−m0 the proton and deuteron invariant spectra deviate from a single exponential shape. The average mt as function of centrality and rapidity is used to explore the effect of collective transverse flow in the reaction. The ratio of the deuteron to squared proton yield as a function of transverse momentum, rapidity, and centrality is used to probe the coalescence model of deuteron production. This ratio is constant as a function of rapidity only for the most central cuts and decreases with the centrality for every rapidity cut. The ratio of the differential cross section of the deuteron to the squared differential cross section of the proton, for the most central cut, is not constant as a function of mt−m0.
- Published
- 1999
306. Centrality dependence of kaon yields inSi+Aand Au+Au collisions at relativistic energies
- Author
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Y. D. Wu, W. A. Zajc, K. Kurita, V. Vutsadakis, S. Y. Fung, F. Videbæk, J. Chang, R. J. Morse, M. Gonin, Hiroyoshi Sakurai, T. Sung, V. Cianciolo, Fuqiang Wang, M. J. LeVine, J. Luke, J. H. Thomas, W. Eldredge, A. Kumagai, H. C. Britt, C. Chasman, H. Sako, J. Engelage, Q. Zhu, Y. Y. Chu, T. C. Sangster, B. Budick, J. C. Dunlop, H. Kaneko, J. J. Gaardhøje, P. Rothschild, Y. Wang, K. Ashktorab, D. S. Woodruff, H. Hamagaki, W. L. Kehoe, S. Homma, R. Seto, J. H. van Dijk, Y. Tanaka, D. R. Beavis, E. G. Judd, H. E. Wegner, C. G. Parsons, J. B. Costales, S. B. Kaufman, P. Beery, Y. Akiba, R. A. Soltz, B. Moskowitz, S. Gushue, George Stephans, X. Yang, Brian Cole, L. P. Remsberg, P. Stankus, L. Ahle, Ole Hansen, Z. Chen, Alex Hansen, S. Tonse, K. Yagi, D. P. Morrison, M. N. Namboodiri, Ryugo S. Hayano, O. Vossnack, R. R. Debbe, S. G. Steadman, G. Heintzelman, Kenta Shigaki, C. Y. Chi, G. H. Xu, S. Nagamiya, J.W. Olness, T. K. Nayak, M. D. Baker, F. Zhu, S. Hayashi, S. Ueno-Hayashi, M. Moulson, C. A. Ogilvie, Yasuo Miake, D. Roehrich, J. B. Cumming, R. J. Ledoux, L. Hansen, M. J. Tannenbaum, J. Kang, H. J. Crawford, and Daniel S. Zachary
- Subjects
Physics ,Nuclear and High Energy Physics ,Nuclear Theory ,Strangeness ,Spectral line ,Nuclear physics ,Mass spectrum ,Transverse mass ,High Energy Physics::Experiment ,Rapidity ,Atomic physics ,Nuclear Experiment ,Centrality ,Nucleon ,Beam energy - Abstract
Charged kaon production has been measured in Si+Al and Si+Au collisions at 14.6 A GeV/c, and Au+Au collisions at 11.1 A GeV/c by Experiments 859 and 866 (the E--802 Collaboration) at the BNL AGS. Invariant transverse mass spectra and rapidity distributions for both K+ and K- are presented. The centrality dependence of rapidity-integrated kaon yields is studied. Strangeness enhancement is observed as an increase in the slope of the kaon yield with the total number of participants as well as the yield per participant. The enhancement starts with peripheral Si+Al and Si+Au collisions (relative to N+N) and appears to saturate for a moderate number of participating nucleons in Si+Au collisions. It is also observed to increase slowly with centrality in Au+Au collisions, to a level in the most central Au+Au collisions that is greater than that found in central Si+A collisions. The enhancement factor for $K^+$ production are 3.0 +-0.2(stat.) +-0.4(syst.) and 4.0 +-0.3(stat.) +-0.5(syst.), respectively, for the most central 7% Si+Au collisions and the most central 4% Au+Au collisions relative to N+N at the correponding beam energy., Comment: RevTeX style, 18 pages, 9 figures, 1 table. Minor changes. Phys. Rev. C in press
- Published
- 1999
307. Measuring centrality with slow protons in proton-nucleus collisions at 18 GeV/c
- Author
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Yanxi Zhang, M. Moulson, Kenneth Francis Read, A. D. Frawley, M. Justice, Richard C. Fernow, Y. H. Shin, R. L. McGrath, G. Rai, D. Winter, W. A. Zajc, V. Cianciolo, N. Maeda, Y. Torun, L. P. Remsberg, D. P. Morrison, R. A. Soltz, I. Chemakin, H. Hiejima, B. A. Cole, E. P. Hartouni, J. H. Kang, M. N. Namboodiri, Harold Kirk, S. Sorensen, M. Rosati, M. L. Gilkes, Saskia Mioduszewski, J. H. Thomas, S. Gushue, and X. Yang
- Subjects
Systematic error ,Physics ,Nuclear and High Energy Physics ,High energy ,Particle physics ,Proton ,010308 nuclear & particles physics ,Nuclear Theory ,01 natural sciences ,Nuclear physics ,medicine.anatomical_structure ,Deuterium ,Computer Science::Multimedia ,0103 physical sciences ,medicine ,Multiplicity (chemistry) ,Nuclear Experiment ,010306 general physics ,Centrality ,Nucleus ,Event generator - Abstract
Experiment E910 has measured slow protons and deuterons from collisions of 18 $\mathrm{GeV}/c$ protons with Be, Cu, and Au targets at the BNL AGS. These correspond to the ``grey tracks'' first observed in emulsion experiments. We report on their momentum and angular distributions and investigate their use in measuring the centrality of a collision, as defined by the mean number of projectile-nucleon interactions. The relation between the measured ${N}_{\mathrm{grey}}$ and the mean number of interactions $\overline{\ensuremath{\nu}}{(N}_{\mathrm{grey}})$ is studied using several simple models, one newly proposed, as well as the RQMD event generator. RQMD is shown to reproduce the ${N}_{\mathrm{grey}}$ distribution, and exhibits a dependence of ${N}_{\mathrm{grey}}$ on centrality that is similar to the behavior of the simple models. We find a strong linear dependence of $\overline{{N}_{\mathrm{grey}}}$ on $\ensuremath{\nu}$, with a constant of proportionality that varies with target. For the Au target, we report a relative systematic error for extracting $\overline{\ensuremath{\nu}}{(N}_{\mathrm{grey}})$ that lies between 10 and 20 % over all ${N}_{\mathrm{grey}}.$
- Published
- 1999
308. THE PHENIX PHYSICS PROGRAM AT RHIC
- Author
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W. A. Zajc
- Subjects
Nuclear physics ,Physics - Published
- 1998
309. H Dibaryon Search in p-A Collisions at the AGS
- Author
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G. Rai, R. A. Soltz, A. D. Frawley, M. Gilkes, Y. Torun, Y. H. Shin, M. Moulson, Kenneth Francis Read, Richard C. Fernow, S. Sorenson, D. Keane, M. Rosati, E. P. Hartouni, H. Hiejima, D. P. Morrison, D. Winter, Xiaodong Yang, N. Maeda, R. L. McGrath, L. R. Remsberg, W. A. Zajc, M. Kreisler, Ju Hwan Kang, Brian Cole, V. Cianciolo, N. Namboodiri, Saskia Mioduszewski, I. Chemakin, Yanxi Zhang, J. H. Thomas, S. Gushue, M. Justice, and H.G. Kirk
- Subjects
Physics ,Time of flight detector ,Spectrometer ,Proton ,Physics::Instrumentation and Detectors ,Cherenkov detector ,Tracking (particle physics) ,Collision ,Particle identification ,law.invention ,Nuclear physics ,Momentum ,law ,High Energy Physics::Experiment ,Nuclear Experiment - Abstract
Experiment 910 at the Brookhaven National Laboratory AGS accelerator is a study of proton-nucleus collisions using 6, 12.5 and 18 GeV/c proton beams. E910 was designed to have close to 100% acceptance, and to provide a large enough data sample to allow particle production to be studied as a function of collision “centrality”. The E910 spectrometer is built around a large TPC, as shown schematically in fig. 1. Because the TPC does not provide good particle identification or momentum resolution at high momentum, these are obtained by including downstream tracking, a time of flight detector and a Cherenkov detector.
- Published
- 1998
310. The Pull of Weird Horizons
- Author
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W. A. Zajc
- Subjects
Physics ,Gravitation ,Theoretical physics ,Multidisciplinary ,Spacetime ,Dark matter - Abstract
Strange Matters . Undiscovered Ideas at the Frontiers of Space and Time. Tom Siegfried. Joseph Henry Press (National Academy Press), Washington, DC, 2002. 317 pp. $24.95, C$34.95. ISBN 0-309-08407-5. In this discussion of "dark matter" and the reconciliation of Einstein's theory of gravity with quantum mechanics, science journalist Siegfried blends accounts of active research with summaries of the historical paths that have led to it.
- Published
- 2003
311. Antiproton production in p+A collisions at 14.6 GeV/c
- Author
-
P. D. Bond, D. S. Woodruff, M. Le Vine, T. Abbott, Hiroyoshi Sakurai, F. Videbæk, Y. Y. Chu, J. Engelage, J. B. Costales, S. Y. Fung, S. Homma, D. R. Beavis, H. Z. Huang, George Stephans, K. Kurita, M. Vient, P. Vincent, C. G. Parsons, Z. Chen, J. H. van Dijk, S. Katcoff, H. E. Wegner, M. J. Tannenbaum, R. R. Debbe, R. J. Morse, B. Moskowitz, S. Gushue, S. G. Steadman, H. J. Crawford, J.W. Olness, I. Juricic, Ole Hansen, W. A. Zajc, V. Vutsadakis, Ryugo S. Hayano, Yuichi Ikeda, Yasuo Miake, Ma Bloomer, D. Roehrich, P. W. Stankus, R. J. Ledoux, K. Kimura, Shinichi Hayashi, J. B. Cumming, S. Nagamiya, Hideki Hamagaki, M. Sarabura, L. P. Remsberg, J. H. Kang, Yang Wu, T. Sugitate, Y. Akiba, Brian Cole, K. Kitamura, and S. B. Kaufman
- Subjects
Nuclear physics ,Nuclear reaction ,Physics ,Nuclear and High Energy Physics ,Antiparticle ,Particle physics ,Antiproton ,Antimatter ,Hadron ,Rapidity ,Alternating Gradient Synchrotron ,Nucleon - Abstract
Antiproton production cross sections have been measured in minimum bias [ital p]+Be, [ital p]+Al, [ital p]+Cu, and [ital p]+Au collisions at 14.6 GeV/[ital c] with the E-802 spectrometer at the Brookhaven Alternating Gradient Synchrotron. The antiproton multiplicity at laboratory rapidities 1.0 to 1.6 shows almost no dependence upon the target mass. The [ital [bar p]] production for [ital p]+Be is somewhat lower than an estimation based upon 19--24 GeV/[ital c] [ital p]+[ital p] data. In this rapidity interval the antiproton yield scales by a factor of 28[plus minus]6 from [ital p]+Au to central Si+Au collisions.
- Published
- 1993
312. Azimuthal asymmetries of particles emitted in relativistic heavy-ion collisions
- Author
-
P. D. Bond, E. Duek, F. Videbæk, Ole Hansen, M. J. Tannenbaum, H. J. Crawford, S. Homma, J. B. Cumming, S. Nagamiya, S. Katcoff, M. Vient, T. Abbott, S. Gushue, B. Moskowitz, R. R. Debbe, S. G. Steadman, Yasuo Miake, H. E. Wegner, Ma Bloomer, L. P. Remsberg, R. J. Ledoux, J. H. Kang, Yang Wu, K. Kimura, P. W. Stankus, Shinichi Hayashi, Y. Y. Chu, J.W. Olness, Brian Cole, D. S. Woodruff, T. Sugitate, S. B. Kaufman, S. Y. Fung, Hiroyoshi Sakurai, George Stephans, Hideki Hamagaki, W. A. Zajc, C. G. Parsons, Z. Chen, J. H. van Dijk, K. Kitamura, V. Vutsadakis, D. R. Beavis, R. J. Morse, Ryugo S. Hayano, M. Sarabura, H. Z. Huang, M. J. LeVine, P. E. Haustein, Yuichi Ikeda, K. Kurita, C. Chasman, Y. Akiba, J. Engelage, J. B. Costales, P. Vincent, and I. Juricic
- Subjects
Nuclear reaction ,Physics ,Meson ,Computer Science::Information Retrieval ,Nuclear Theory ,Hadron ,General Physics and Astronomy ,Elementary particle ,Charged particle ,Nuclear physics ,Baryon ,Rapidity ,Atomic physics ,Nuclear Experiment ,Nucleon - Abstract
Experimental particle yield ratios from 14.6[ital A]-GeV/[ital c][sup 28]Si interactions with nuclei at intermediate impact parameters are correlated with the orientation of the transverse momentum of projectile fragments. The [pi][sup [plus minus]]/[ital p] ratio increases and the ([ital d]+[ital t])/[ital p] ratio decreases when fragments are deflected toward the observing spectrometer. Asymmetries are confined to the target rapidity region. Assuming a spectator participant model, these results suggest the presence of significant rescattering of particles with dependences on the collision geometry.
- Published
- 1993
313. A Pedestrian’s Guide to Interferometry
- Author
-
W. A. Zajc
- Subjects
Physics ,Nuclear physics ,Strange matter ,Correlation function (statistical mechanics) ,Interferometry ,Large Hadron Collider ,High Energy Physics::Phenomenology ,Nuclear Theory ,State of matter ,Plasma ,Nuclear Experiment ,Deconfinement ,Identical particles - Abstract
In the collision of two heavy ions at RHIC or LHC energies, it is thought that a quark-gluon plasma will be formed. The defining characteristic of such a state of matter is a deconfinement region significantly larger than the ∼ 1 fm radii of the individual hadrons. The only direct method of probing the spatial distribution of hadronic collisions is to measure correlations between pairs of emitted particles. This approach, especially when applied to pairs of identical particles, is usually referred to as Hanbury-Brown-Twiss (HBT) interferometry, in recognition of the pioneering work of Hanbury-Brown and Twiss[1] in applying this technique to optical astronomy.
- Published
- 1993
314. Bose-Einstein correlations in Si+Al and Si+Au collisions at 14.6A GeV/c
- Author
-
T. Abbott, Y. Akiba, D. Beavis, M. A. Bloomer, P. D. Bond, C. Chasman, Z. Chen, Y. Y. Chu, B. A. Cole, J. B. Costales, H. J. Crawford, J. B. Cumming, R. Debbe, J. Engelage, S. Y. Fung, S. Gushue, H. Hamagaki, O. Hansen, R. S. Hayano, S. Hayashi, S. Homma, H. Z. Huang, Y. Ikeda, I. Juricic, J. Kang, S. Katcoff, S. Kaufman, K. Kimura, K. Kitamura, K. Kurita, R. J. Ledoux, M. J. Levine, Y. Miake, R. J. Morse, B. Moskowitz, S. Nagamiya, J. Olness, C. G. Parsons, L. P. Remsberg, H. Sakurai, M. Sarabura, P. Stankus, S. G. Steadman, G. S. F. Stephans, T. Sugitate, M. J. Tannenbaum, J. H. Van Dijk, F. Videbaek, M. Vient, V. Vutsadakis, H. E. Wegner, D. S. Woodruff, Y. D. Wu, and W. A. Zajc
- Subjects
Physics ,Meson ,Hadron ,General Physics and Astronomy ,Alternating Gradient Synchrotron ,Bose–Einstein correlations ,Nuclear physics ,symbols.namesake ,Correlation function (statistical mechanics) ,Pion ,Bose–Einstein statistics ,symbols ,Rapidity ,Atomic physics ,Nuclear Experiment - Abstract
The E802 Spectrometer at the Brookhaven Alternating Gradient Synchrotron has been used to measure the correlation in relative momentum between like-sign pions emitted in central Si + Al and Si + Au collisions at 14.6A GeV/c. Data are presented in terms of the correlation function for both identified pi(-) and pi(+) pairs near the nucleon-nucleon center-of-mass rapidity. All parametrizations of the correlation function are consistent with a spherically symmetric source of rms radius 3.5 +/- 0.4 fm and lifetime fm/c.
- Published
- 1992
315. Measurement of particle production in proton-induced reactions at 14.6 GeV/c
- Author
-
J. Engelage, P. D. Bond, M. J. Tannenbaum, Y. Akiba, Yasuo Miake, M. Vient, M. Sarabura, J. B. Cumming, J.W. Olness, C. G. Parsons, B. Moskowitz, S. Katcoff, S. Homma, D. Beavis, M. J. LeVine, Ryugo S. Hayano, R. Debbe, S. G. Steadman, Yuichi Ikeda, H. J. Crawford, C. Chasman, B. Cole, Y. D. Wu, R. J. Ledoux, K. Kimura, S. Y. Fung, O. Hansen, M. A. Bloomer, R. J. Morse, T. Abbott, P. Stankus, S. Nagamiya, W. A. Zajc, K. Kurita, V. Vutsadakis, L. P. Remsberg, J. H. Kang, F. Videbaek, T. Sugitate, H. E. Wegner, G. S. F. Stephans, Hiroyoshi Sakurai, Y. Y. Chu, S. Gushue, D. S. Woodruff, Z. Chen, J. H. van Dijk, S. B. Kaufman, H. Z. Huang, S. Hayashi, H. Hamagaki, J. B. Costales, K. Kitamura, P. Vincent, and I. Juricic
- Subjects
Physics ,Nuclear reaction ,Proton ,Nuclear Theory ,Hadron ,Elementary particle ,Synchrotron ,Particle detector ,law.invention ,Nuclear physics ,Baryon ,law ,High Energy Physics::Experiment ,Atomic physics ,Nuclear Experiment ,Nucleon - Abstract
Particle production in proton-induced reactions at 14.6 GeV/{ital c} on Be, Al, Cu, and Au targets has been systematically studied using the E-802 spectrometer at the BNL-Alternating Gradient Synchrotron. Particles are measured in the angular range from 5{degree} to 58{degree} and identified up to momenta of 5, 3.5, and 8 GeV/{ital c} for pions, kaons, and protons, respectively. Mechanisms for particle production are discussed in comparison with heavy-ion-induced reactions at the same incident energy per nucleon.
- Published
- 1992
316. Particle production in pA and AA collisions at AGS
- Author
-
Y. Akiba, H. Z. Huang, S. Nagamiya, J. B. Cumming, J. Engelage, R. J. Ledoux, K. Kimura, Shinichi Hayashi, J. B. Costales, M. J. Tannenbaum, Z. Chen, Yasuo Miake, Ma Bloomer, J. H. van Dijk, H. J. Crawford, W. A. Watson, Russell Richard Betts, M. Sarabura, P. W. Stankus, D. S. Woodruff, R. J. Morse, S. Katcoff, S. B. Kaufman, S. Homma, David E. Alburger, S. Gushue, Ryugo S. Hayano, George Stephans, P. Vincent, Yuichi Ikeda, Lee Grodzins, T. Abbott, Hiroyoshi Sakurai, J. H. E. Wegner, F. Videbæk, K. Kitamura, Presented by Yasuo Miake, M. Vient, J.W. Olness, R. R. Debbe, M. J. LeVine, K. Kurita, M. Torikoshi, S. Y. Fung, S. G. Steadman, I. Juricic, Brian Cole, C. Chasman, P. D. Bond, Hideki Hamagaki, Toru Sugitate, D. R. Beavis, Y. Y. Chu, L. P. Remsberg, M. Tanaka, Yang Wu, Ole Hansen, W. A. Zajc, V. Vutsadakis, C. G. Parsons, and B. Moskowitz
- Subjects
Nuclear physics ,Physics ,Pion ,Photon ,Proton ,Particle ,Atomic physics - Abstract
Production of light particles (π±,K ±,p) has been measured in both Si+A and p+A collisions. Several interesting features have been observed, among which are: the enhanced K +/π+ ratio and the larger 〈m t 〉 for K + and proton. Comparisons between ≊pp, pA and SiA collisions are discussed.
- Published
- 1992
317. The E859 level II trigger system
- Author
-
W. A. Zajc
- Subjects
Nuclear physics ,Physics ,Particle physics ,Spectrometer ,Antiproton ,Measuring instrument ,Level trigger ,Level ii ,Isotopes of gold ,Isotopes of silicon ,Particle identification - Abstract
A second level trigger with online particle identification has been developed for experiment E859, at the BNL AGS. It is designed to provide enhanced trigger rates for 2π+/−, 2K+, K− and p events in Si+Au collisions at 14.6⋅A(GeV/c) by rejecting undesirable events selected at Level I. The trigger, implemented largely with commercially available LeCroy readout modules and memory lookup units, finds tracks, and determines their momenta and masses within 40 μs.
- Published
- 1992
318. Strangeness in quark matter 2008—experimental summary
- Author
-
W. A. Zajc
- Subjects
Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Strange matter ,Particle physics ,Astrophysics::High Energy Astrophysical Phenomena ,High Energy Physics::Phenomenology ,Heavy ion ,Strangeness ,Nuclear Experiment - Abstract
This contribution is a reprise of my summary talk at the conference, attempting to capture the experimental status of flavor dynamics in relativistic heavy ion collisions circa October 2008.
- Published
- 2009
319. Pion correlations in relativistic heavy ion collisions for three symmetric systems
- Author
-
M. A. Stoyer, Kenneth M. Crowe, Osamu Hashimoto, S. Ljungfelt, James A. Bistirlich, H. R. Bowman, CA Petitjean, R. Bossingham, A. D. Chacon, H. Bossy, J. M. Kurck, P. Kammel, M. Justice, W. A. Zajc, J. P. Sullivan, T. J. Humanic, K.L. Wolf, C. W. Clawson, John O. Rasmussen, Wm. C. McHarris, and C. A. Meyer
- Subjects
Nuclear reaction ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Meson ,Nuclear Theory ,Hadron ,Elementary particle ,Pion ,Center of mass ,Atomic physics ,Nuclear Experiment ,Nucleon ,Boson - Abstract
The method of two-pion interferometry was used to obtain source-size and lifetime parameters for the pions produced in heavy ion collisions. Two acceptances (centered at approximately 0\ifmmode^\circ\else\textdegree\fi{} and approximately 90\ifmmode^\circ\else\textdegree\fi{}, in the center of mass) were used for each of three systems, 1.70 GeV/nucleon $^{56}\mathrm{Fe}$+Fe, 1.82 GeV/nucleon $^{40}\mathrm{Ar}$+KCl, and 1.54 GeV/nucleon $^{93}\mathrm{Nb}$+Nb, allowing a search for dependences on nuclear mass and viewing angle. The correlation functions were calculated by comparing data samples to event-mixed reference samples. The effect of the particle correlations on the reference samples was corrected by weighting the events appropriately to remove the residual correlation effect. The source parameters, in the nucleus-nucleus center-of-mass frame, show an oblate source (i.e., ${\mathit{R}}_{\mathrm{\ensuremath{\perp}}}$g${\mathit{R}}_{\mathrm{\ensuremath{\parallel}}}$) for the lighter systems and an approximately spherical source for the heaviest system. The dependence on nuclear mass shows that ${\mathit{R}}_{\mathrm{\ensuremath{\perp}}}$ is essentially constant (under both viewing angles), whereas ${\mathit{R}}_{\mathrm{\ensuremath{\parallel}}}$ for the 90\ifmmode^\circ\else\textdegree\fi{} (c.m.) data increases with the nuclear mass. No evidence was found for a dependence of the source size on the pion momentum.
- Published
- 1991
320. High-pT charged hadron suppression in Au+Au collisions at √sNN=200 GeV
- Author
-
T. Ichihara, A. Litvinenko, M. A. Volkov, A. Isupov, F. K. Wohn, T. K. Ghosh, Matthew G. Reuter, T. L. Thomas, David D'Enterria, H. Tsuruoka, C. A. Ogilvie, S. Bathe, R. P. Pisani, V. Ladygin, M. Gonin, T. K. Hemmick, Kensuke Homma, Yasuo Miake, N. N. Ajitanand, Nikolay Tyurin, E. Melnikov, S. Afanasiev, X. He, Y. J. Kwon, Takahiro Nakamura, R. A. Soltz, Ryugo S. Hayano, M. E. Sadler, S. Chernichenko, H. Lim, A. Ster, L. Sanfratello, I. D. Ojha, Alexander Malakhov, V. Peresedov, B. Bassalleck, F. Mühlbacher, K. Kurita, S. Borenstein, L. Ewell, A. Durum, Y. Kuroki, W. Y. Jang, Y. Riabov, B. D. Fox, Kenta Shigaki, M. Sivertz, M. Grosse Perdekamp, D. S. Brown, Norio Saito, V. Bumazhnov, A. S. Nyanin, M. Issah, H. Masui, F. Messer, P. D. Barnes, A. Yanovich, N. Kamihara, S. Garpman, M. Heffner, E. Vznuzdaev, V. Baublis, V. Babintsev, Jen-Chieh Peng, S. S. Adler, G. S. Kyle, F. Matathias, David Olle Rickard Silvermyr, James Alexander, P. Tarján, J. Chiba, M. Sakai, W. C. Chang, T. Shiina, D. E. Fields, B. V. Jacak, G. Gogiberidze, Y. Jeong, R. Averbeck, A. Drees, Byung-Sik Hong, S. Sawada, A. Bazilevsky, J. D. Tepe, A. Franz, O. Dietzsch, V. S. Pantuev, H. A. Gustafsson, M. Harvey, Roy A. Lacey, Philippe Rosnet, S. N. White, Charles Maguire, S. Leckey, A. K. Purwar, G. C. Mishra, Alexandre Lebedev, E. J. Desmond, S. S. Kapoor, Dipanwita Dutta, Junji Tojo, J. B. Choi, D. M. Lee, Martin Purschke, Takao Sakaguchi, S. Butsyk, B. Khachaturov, Vladimir Samsonov, I. Otterlund, Sean A. Kelly, L. Aphecetche, R. E. Mischke, C. Zhang, C. Klein-Boesing, R. du Rietz, Josh Moss, K. Okada, S. P. Stoll, Julia Velkovska, M. Hibino, J. T. Mitchell, E. P. Hartouni, H. En'yo, P. Constantin, A. G. Hansen, Shingo Sakai, W. E. Sondheim, T. Matsumoto, M. Tamai, A. D. Frawley, J. Park, Vladislav Manko, M. D. Marx, Dong Jo Kim, G. Bunce, Osamu Jinnouchi, M. J. Leitch, E. Kistenev, D. Isenhower, H. W. Van Hecke, C. L. Woody, S. Y. Fung, Joakim Nystrand, J. L. Nagle, T. Chujo, S. H. Aronson, X. Camard, M. Rosati, M. Velkovsky, A. Kozlov, R. Seto, D. Jouan, G. R. Young, V. Kochetkov, A. Parmar, Senta Greene, M. Nara, W. Holzmann, John Hill, K. Oyama, Christine Angela Aidala, R. Amirikas, S. F. Pate, D. Kotchetkov, Viktor Riabov, S. Bhagavatula, A. A. Vinogradov, Henrik Tydesjö, Jiangyong Jia, Y. I. Makdisi, J. E. Frantz, Toru Sugitate, C. P. Singh, I. E. Yushmanov, I. V. Sourikova, H. Torii, Shih-Chang Lee, K. S. Sim, X. R. Wang, Y. Tanaka, Y. Goto, Alexander Milov, S. L. Fokin, K. N. Barish, P. Chand, E. O'Brien, O. Drapier, T. K. Shea, Alexei Khanzadeev, S. Batsouli, T. C. Awes, Wei Xie, V. Papavassiliou, Z. Fraenkel, R. K. Choudhury, A. Deshpande, N. Bruner, E. Stenlund, François Fleuret, M. J. Tannenbaum, M. Ono, L. Kochenda, K. Imai, D. P. Morrison, V. E. Semenov, V. V. Ikonnikov, Jun Kikuchi, H. Kobayashi, Jan Rak, W. Guryn, S. C. Johnson, Agneta Oskarsson, Y. J. Mao, M. J. Kweon, A. P.T. Palounek, R. Granier de Cassagnac, D. Bucher, Y. Berdnikov, H. J. Kim, S. Esumi, K. Ozawa, I. Tserruya, Y. Akiba, Yu. Efremenko, M. L. Brooks, V. Singh, Kazuhiro Tanaka, S. Nagamiya, L. Villatte, Klaus Johannes Reygers, G. B. Kim, D. Koehler, W. A. Zajc, J. S. Chai, Herve Borel, A. Denisov, V. Cianciolo, E. Kim, A. Hoover, Atsushi Taketani, V.A. Onuchin, P. L. McGaughey, Hirohiko Sato, S. K. Tuli, S. Belikov, K. S. Joo, J. M. Burward-Hoy, K. El Chenawi, M. R. Shaw, N. Grau, Jason Newby, A. Glenn, J. Murata, Minghui Liu, Kenneth Francis Read, L. Zolin, P. W. Stankus, Do-Won Kim, P. J. Kroon, Dong-Hun Kim, S. P. Sorensen, Peter M. Nilsson, Hideki Hamagaki, J. G. Lajoie, T. Hachiya, I. J. Choi, Hiroaki Ohnishi, J. Milan, G. David, C. H. Kuberg, H. Buesching, Xingguo Li, Y. Yang, B. M. Johnson, H. Delagrange, R. S. Towell, Yanwen Liu, M. Kopytine, S. Zhou, M. Chiu, Ajit Kumar Mohanty, T. A. Shibata, K. Kiyoyama, C. Y. Chi, B. K. Nandi, S. Kametani, T. Peitzmann, Saskia Mioduszewski, J. H. Kang, J. S. Haggerty, A. Romana, Yves Roland Schutz, German Martinez, J. M. Heuser, D. Pal, E. M. Takagui, B. A. Cole, J. Gosset, J. P. Sullivan, S. Yokkaichi, T. E. Miller, J. G. Boissevain, K. Katou, R. Santo, A. Enokizono, A. Kiyomichi, C. Pinkenburg, M. Stepanov, G. Roche, Y. Watanabe, A. Soldatov, K. Tanida, Alberto Baldisseri, C. L. Silva, T. Kohama, Masayasu Ishihara, Susumu Sato, M. Muniruzzaman, F. Staley, I. Ravinovich, F. Plasil, S. S. Ryu, R. Azmoun, D. Mukhopadhyay, Y. Cobigo, Laboratoire SUBATECH Nantes (SUBATECH), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Nantes (UN)-Mines Nantes (Mines Nantes), Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), PHENIX, Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Nuclear and High Energy Physics ,Particle physics ,quark-gluon plasma ,Hadron ,Nuclear Theory ,pion production ,FOS: Physical sciences ,nuclei with mass number 190 to 219 ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,01 natural sciences ,Spectral line ,Nuclear physics ,Pion ,heavy ion-nucleus scattering ,0103 physical sciences ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nuclear Experiment ,Physics ,hadron production ,010308 nuclear & particles physics ,Antiproton ,Quark–gluon plasma ,High Energy Physics::Experiment ,Relativistic Heavy Ion Collider ,Centrality - Abstract
The PHENIX experiment at RHIC has measured charged hadron yields at mid-rapidity over a wide range of transverse momentum (0.5 < p_T < 10 GeV/c) in Au+Au collisions at sqrt(s_NN)=200 GeV. The data are compared to pi^zero measurements from the same experiment. For both charged hadrons and neutral pions, the yields per nucleon-nucleon collision are significantly suppressed in central compared to peripheral and nucleon-nucleon collisions. The suppression sets in gradually and increases with increasing centrality of the collisions. Above 4-5 GeV/c in p_T, a constant and almost identical suppression of charged hadrons and pi^zeroes is observed. The p_T spectra are compared to published spectra from Au+Au at sqrt(s_NN)=130 in terms of x_t scaling. Central and peripheral pi^zero as well as peripheral charged spectra exhibit the same x_t scaling as observed in p+p data., 325 authors, 22 pages text, 18 figures, 6 tables, RevTeX 4. Minor revisions to address referee concerns during journal review. Now published in Physical Review C as a regular article. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are publicly available at http://www.phenix.bnl.gov/papers.html
- Published
- 2004
321. Two-pion correlations in heavy ion collisions
- Author
-
E. Yoo, J. P. Miller, Kenneth M. Crowe, K.A. Frankel, H. R. Bowman, John O. Rasmussen, C. J. Martoff, Osamu Hashimoto, W.J. McDonald, J. M. Kurck, James A. Bistirlich, W. A. Zajc, C. W. Clawson, J. P. Sullivan, J. G. Ingersoll, D. L. Murphy, P. Truöl, R. Bossingham, and Masahiro Koike
- Subjects
Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Correlation function (statistical mechanics) ,Pion ,Pair production ,Meson ,Monte Carlo method ,Hadron ,Coulomb ,Impact parameter ,Nuclear Experiment - Abstract
An application of intensity interferometry to relativistic heavy ion collisions is reported. The correlation between two like-charged pions is used to study the reactions Ar+KC1..-->..2..pi../sup + -/+X and Ne+NaF..-->..2..pi../sup -/+X, both at an incident beam energy of 1.8A GeV. Source sizes and lifetimes are measured and compared to the predictions of simple geometric models and of Monte Carlo cascade calculations. There appears to be a substantial coherent component of the pion source, although measurement is complicated by the presence of final state interactions. A detailed discussion of the techniques of intensity interferometry is also presented. The generation of uncorrelated background events is discussed, along with the influence of the correlation on the background and the prescription for its removal. The statistical errors in the background spectrum are examined and found to have nontrivial implications for the analysis. The effect of the mutual Coulomb repulsion of the two pions, and of the pion-nuclear Coulomb interaction, on the two-pion correlation function is analyzed. The impact parameter bias resulting from a two-pion trigger is calculated and found to be substantial. Finally, a simple model for the interpretation of Gaussian source parameters is presented and compared to the predictions of Monte Carlo cascade calculations.
- Published
- 1984
322. KNO scaling isn't what it used to be
- Author
-
W. A. Zajc
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,Negative binomial distribution ,Context (language use) ,Multiplicity (mathematics) ,Statistical physics ,Scaling - Abstract
The definition of KNO scaling is reviewed in the context of the negative binomial distributions. It is shown that these distributions provide a natural description of observed violations of KNO scaling. The properties of the negative binomial distribution are then used to predict the correlations between photons and charged-particle production, and the forward-backward multiplicity correlations.
- Published
- 1986
323. Strong Coulomb effects on pions produced in heavy ion collisons
- Author
-
K.A. Frankel, John O. Rasmussen, C. J. Martoff, W. Benenson, R. Bossingham, J. Péter, W. A. Zajc, Jerry Nolen, Kenneth M. Crowe, H. R. Bowman, D. L. Murphy, O. Hashimoto, T. Buttke, J. P. Sullivan, G.M. Crawley, M. Koike, E. Kashy, James A. Bistirlich, and J. P. Miller
- Subjects
Physics ,Nuclear reaction ,Nuclear and High Energy Physics ,Pion ,Pair production ,Meson ,Hadron ,Coulomb ,Elementary particle ,Atomic physics ,Nuclear Experiment ,Boson - Abstract
Doubly differential cross sections for the production of ${\ensuremath{\pi}}^{+}$ and ${\ensuremath{\pi}}^{\ensuremath{-}}$ near the velocity of the incident beam for pion laboratory angles from 0 to 20 degrees are presented. Beams of $^{20}\mathrm{Ne}$ with $\frac{E}{A}=280, 380, \mathrm{and} 480$ MeV and $^{40}\mathrm{Ar}$ with $\frac{E}{A}=535$ MeV incident on C, NaF, KCl, Cu, and U targets were used. A sharp peak in the ${\ensuremath{\pi}}^{\ensuremath{-}}$ spectrum and a depression in the ${\ensuremath{\pi}}^{+}$ spectrum is observed at 0\ifmmode^\circ\else\textdegree\fi{} near the incident projectile velocity. The effect is explained in terms of Coulomb interactions between pions and fragments of the incident beam. Least squares fits to the data using the Coulomb correction formulas of Gyulassy and Kauffmann and an effective projectile fragment charge are made. The relationship between these data and previously measured projectile fragmentation data is discussed and a simple parametrization of projectile mass, target mass, and beam energy dependence of the differential cross sections is given.NUCLEAR REACTIONS C, NaF, Cu, U $(^{20}\mathrm{Ne},{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}})X$, $\frac{E}{A}=280\ensuremath{-}480$ MeV; C, KCl $(^{40}\mathrm{Ar},{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}})X$, $\frac{E}{A}=535$ MeV; measured $\ensuremath{\sigma}({E}_{\ensuremath{\pi}},{\ensuremath{\theta}}_{\ensuremath{\pi}})$, ${\ensuremath{\theta}}_{\ensuremath{\pi}}=0\ifmmode^\circ\else\textdegree\fi{}\ensuremath{-}20\ifmmode^\circ\else\textdegree\fi{}$, $\ensuremath{\pi}$ velocity near beam velocity; deduced projectile fragment charges, Coulomb effects.
- Published
- 1982
324. Particle spectra near mid-rapidity studied with Cherenkov-complex system in 14.5 AGEV SI + AU collisions
- Author
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M. Vient, H. Hamagaki, P. D. Bond, W. A. Watson, C. G. Parsons, Yasuo Miake, R. J. Morse, H. J. Crawford, O. Hansen, L. P. Remsberg, K. Kitamura, G. S. F. Stephans, H. Z. Huang, B. A. Cole, Toru Sugitate, S. Nagamiya, S. Homma, R. J. Ledoux, D. R. Beavis, J. Engelage, M. J. LeVine, Y. D. Wu, M. J. Tannenbaum, F. Videbaek, M. A. Bloomer, M. Torikoshi, W. A. Zajc, M. Tanaka, C. Chasman, K. Kurita, L. Grodzins, D. S. Woodruff, H. E. Wegner, V. Vutsadakis, J.W. Olness, P. Stankus, Yuichi Ikeda, J. B. Costales, K. Kimura, S. G. Steadman, S. B. Kaufman, S. Y. Fung, M. Sarabura, L. Birstein, J. H. van Dijk, A. Shor, R. R. Debbe, P. Vincent, J. B. Cumming, Hideki Hamagaki, E. Duek, S. Hayashi, R. R. Betts, S. Katcoff, David E. Alburger, S. Gushue, T. Abbott, Y. Akiba, and Y. Y. Chu
- Subjects
Physics ,Nuclear and High Energy Physics ,Nuclear Theory ,Complex system ,Spectral line ,Nuclear physics ,Pion ,Particle ,High Energy Physics::Experiment ,Heavy ion ,Rapidity ,Atomic physics ,Nuclear Experiment ,Cherenkov radiation - Abstract
The Cherenkov Complex system (CC-system) in the E-802 experiment at AGS was successfully operated in the heavy ion running at AGS. Brief description of the system is given. Preliminarily obtained particle spectra for pions, Kaons, and protons near mid-rapidity region in 14.5 A.GeV Si + Au collisions are presented. The spectra shape and the relative yields are compared with those in p + ‘N’ and p + Au collisions.
- Published
- 1989
325. Search for Quark Deconfinement: Strangeness Production inpp,dd,pα, andααCollisions atsNN=31.5 and 44GeV
- Author
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T. Åkesson, M. G. Albrow, S. Almehed, O. Benary, H. Bøggild, O. Botner, H. Breuker, H. Brody, V. Burkert, B. Callen, A. A. Carter, J. R. Carter, P. Cecil, Y. Choi, W. E. Cleland, P. Dam, S. Dagan, E. Dahl-Jensen, I. Dahl-Jensen, G. Damgaard, W. M. Evans, C. W. Fabjan, P. Frandsen, S. Frankel, W. Frati, H. Gordon, U. Goerlach, K. H. Hansen, V. Hedberg, J. E. Hooper, G. Jarlskog, G. Kessler, T. Killian, R. Kroeger, K. Kulka, J. v. d. Lans, D. Lissauer, B. Lörstad, T. Ludlam, N. A. McCubbin, R. Møller, M. Molzon, B. S. Nielsen, L. H. Olsen, Y. Oren, E. Rosso, A. Rudge, H. Specht, I. Stumer, J. A. Thompson, G. Thorstensen, E. Vella, J. W. Williamson, W. J. Willis, W. Witzeling, C. Woody, and W. A. Zajc
- Subjects
Nuclear physics ,Quark ,Physics ,Particle physics ,Meson ,General Physics and Astronomy ,Strangeness production ,Production (computer science) ,Multiplicity (mathematics) ,Rapidity ,Nuclear Experiment ,Deconfinement - Abstract
Relative yields of $\ensuremath{\varphi}$ and charged $K$ mesons are measured as functions of charged multiplicity in the central rapidity region for $\mathrm{pp}$, $\mathrm{dd}$, $p\ensuremath{\alpha}$, and $\ensuremath{\alpha}\ensuremath{\alpha}$ collisions at $\sqrt{{s}_{\mathrm{NN}}}=3.15 \mathrm{and} 44$ GeV. No anomalous strange-particle production is observed in $\ensuremath{\alpha}\ensuremath{\alpha}$ reactions relative to $\mathrm{pp}$ even at large multiplicities corresponding to events comprising less than 3.6\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}4}$ of the inclusive cross section.
- Published
- 1985
326. Measurement of energy emission from O+A and p+A collisions at 14.5 GeV/c per nucleon with a lead-glass array
- Author
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W. A. Watson, Yasuo Miake, D. S. Woodruff, Ma Bloomer, Y. Akiba, L. Grodzins, S. Gushue, A.W. Sunyar, M. J. Tannenbaum, Hideki Hamagaki, J. Engelage, J. B. Cumming, O. Hansen, S. B. Kaufman, P. Vincent, D.E. Greiner, P. D. Bond, T. Abbott, Y. Y. Chu, M. Sarabura, A. Shor, D. Alburger, W. A. Zajc, M. Le Vine, R.R. Betts, J.B. Costales, H.A. Enge, J. H. van Dijk, V. Vutsadakis, C. G. Parsons, P.E. Haustein, George Stephans, S. Y. Fung, C. Chasman, Toru Sugitate, D. R. Beavis, R. J. Morse, R. R. Debbe, S. G. Steadman, P. J. Lindstrom, S. Homma, E. Duek, H. E. Wegner, M. Torikoshi, Hank Crawford, B.A. Cole, S. Nagamiya, J.W. Olness, H.N. Huang, Yuichi Ikeda, L. P. Remsberg, Shinichi Hayashi, F. Videbaek, M.A.J. Mariscotti, M. Tanaka, E. Vulgaris, and S. Katcoff
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,Nuclear Theory ,lcsh:QC1-999 ,Nuclear physics ,Lead glass ,visual_art ,Energy spectrum ,visual_art.visual_art_medium ,Total energy ,Nuclear Experiment ,Nucleon ,lcsh:Physics ,Energy (signal processing) ,Beam (structure) - Abstract
The first data from a 16O beam of total energy 232 GeV at the BNL Tandem-AGS are reported. A lead-glass array covering the laboratory pseudo-rapidity interval 1.25 < η < 2.44 recorded the energy emitted from 16O interactions in Au, Cu, and Mylar and from proton interactions in Au. The shapes of the energy spectra imply that a nucleon loses most of its energy in the first few collisions. Consequently a simple description of the observed 16O+Cu and 16O+Au spectra as a properly weighted convolution of the observed p + Au spectrum is obtained. It is shown that 16O nuclei at this energy can be substantially stopped by nuclei of the size of Cu. An estimate of the energy density for central collisions is given.
- Published
- 1987
327. Proton production from Si+Au collisions at 14.5 A-GeV
- Author
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J. B. Costales, J.W. Olness, P. Vincent, R. R. Debbe, S. Y. Fung, M.A.J. Mariscotti, H.A. Enge, E. Vulgaris, Toru Sugitate, S. Nagamiya, D. R. Beavis, P. Stankus, O. Hansen, M. J. Tannenbaum, W. A. Watson, J. Engelage, T. Abbott, H. Hamagaki, B. Wadsworth, A. Shor, P. E. Haustein, H. J. Crawford, G. S. F. Stephans, Russell Richard Betts, E. Duek, S. Hayashi, V. Vutsadakis, S. G. Steadman, L. Grodzins, P.J. Lindstrom, Brian Cole, S. Homma, M. Tanaka, Y. D. Wu, D. S. Woodruff, P. D. Bond, M. Torikoshi, W. A. Zajc, K. Kurita, David E. Alburger, S. Gushue, S. Katcoff, H. E. Wegner, L. P. Remsberg, F. Videbaek, R. J. Ledoux, D.E. Greiner, Y. Y. Chu, M. J. LeVine, C. Chasman, J. H. van Dijk, C. G. Parsons, Yuichi Ikeda, Yasuo Miake, R. Lanza, Ma Bloomer, M. Sarabura, K. Kitamura, J. B. Cumming, S. B. Kaufman, H. Z. Huang, L. Birstein, R. J. Morse, and Y. Akiba
- Subjects
Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Proton ,Thermal source ,Rapidity ,Atomic physics - Abstract
Recent results are presented from the study of central Si+Au → p+X, Si+Au → π±+X, and Si+Cu → p+X at 14.5 A.GeV. The distribution of protons in rapidity indicates that many target protons are found above 0.5 units. The variation of the slope parameter in rapidity is consistent with a thermal source of protons at the geometric center-of-mass rapidity.
- Published
- 1989
328. Measurements of in collisions of light nuclei at
- Author
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R. Møller, Michael Albrow, L. H. Olsen, Yona Oren, I. Dahl-Jensen, K. Kulka, E. Vella, S. Dagan, Göran Jarlskog, W. A. Zajc, J. E. Hooper, R. Kroeger, O. Botner, W. Frati, N. A. McCubbin, Sherman Frankel, Horst Breuker, H. Bøggild, J. R. Carter, Borge Svane Nielsen, E. Dahl-Jensen, B. Lörstad, Vincent Hedberg, C.W. Fabjan, Ulrich Goerlach, A. A. Carter, W. R. Molzon, Torsten Paul Ake Åkesson, B. Callen, G. Damgaard, Y. Choi, S. Almehed, and Odette Benary
- Subjects
Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Particle physics ,Light nucleus ,Calorimeter (particle physics) ,Pseudorapidity ,Interval (graph theory) ,High Energy Physics::Experiment ,Nuclear Experiment ,Nucleon - Abstract
Calorimeter measurements of dσ de t for pp, dd, pα , and αα collisions at S nn =31.5 GeV are presented for the pseudorapidity interval | η cm | ⩽ 0.7, extending over eight decades to E t ⩾ 30 GeV. The data are compared with models that predict nuclear cross sections directly from pp data, under the assumption of independent nucleon scatters.
- Published
- 1989
329. Production of prompt positrons at low transverse momentum in 63 GeV pp collisions at the CERN intersecting storage rings
- Author
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W. A. Zajc, A. A. Carter, P. Jeffreys, R. Carosi, S. Eidelman, I. Mannelli, G. Damgaard, L. K. Resvanis, H. J. Specht, P. Cecil, Göran Jarlskog, G. Piskounov, M. D. Gibson, Torsten Paul Ake Åkesson, H. Bøggild, Sherman Frankel, C. L. Woody, Odette Benary, A. Kalinovsky, K. H. Hansen, W. Frati, J. W. Hiddleston, Y. Choi, B. Lörstad, N. A. McCubbin, T. Killian, S. Mayburov, W. R. Molzon, S. Katsanevas, C.W. Fabjan, M. Winik, Christine Kourkoumelis, Pavlos Ioannou, V. Chernyatin, J. v. d. Lans, I. Dahl-Jensen, E. Anassontzis, E. Dahl-Jensen, J. R. Carter, M. Sullivan, W. M. Evans, I. Stumer, K. Kulka, L. H. Olsen, Howard Gordon, W. J. Willis, P. Frandsen, Michael Albrow, E. Vella, O. Botner, Vincent Hedberg, Ulrich Goerlach, B. Dolgoshein, Y. Goloubkov, Richard Batley, P. Nevsky, T. W. Ludlam, V. Kantserov, Volker D. Burkert, Yona Oren, S. Dagan, R. B. Palmer, G. Thorstenson, J.G. Williamson, Ulf Mjörnmark, G. Kesseler, B. Callen, J. Lindsay, P. Vasiliev, H. Brody, V. Sidorov, A. Rudge, P. Dam, E. Rosso, S. Almehed, T. Jensen, Borge Svane Nielsen, J. A. Thompson, Alevtina Shmeleva, R. Møller, Jurgen Schukraft, D.C. Rahm, W. Cleland, Horst Breuker, A. Markou, R. Kroeger, W. Witzeling, D. Lissauer, I. Gavrilenko, and J. E. Hooper
- Subjects
Semileptonic decay ,Physics ,Nuclear and High Energy Physics ,Particle physics ,Large Hadron Collider ,Intersecting Storage Rings ,Astrophysics::High Energy Astrophysical Phenomena ,Hadron ,Bremsstrahlung ,Nuclear physics ,Positron ,Transverse momentum ,High Energy Physics::Experiment ,Charm (quantum number) ,Nuclear Experiment ,Particle Physics - Experiment - Abstract
The production of inclusive prompt positrons in pp collisions at √ s = 63 GeV and θ cm = 90° has been measured over the p T interval 0.08 T GeV c . The e / π ratio rises from ∼ 2 × 10 −4 at p T = 0.9 GeV c to ∼ 1 × 10 −3 at p T = 0.1 GeV c . This is a factor of 6 higher than would be expected from the sum of hadronic bremsstrahlung and the semileptonic decay of charm.
- Published
- 1985
330. Rapidity and charge correlations of centrally produced charged particles in events with a high-momentumπ0near 11°
- Author
-
T. Akesson, M. G. Albrow, S. Almehed, R. Batley, O. Benary, H. Boggild, O. Botner, H. Breuker, H. Brody, V. Burkert, B. Callen, R. Carosi, A. A. Carter, J. R. Carter, P. Cecil, Y. Choi, W. E. Cleland, S. Dagan, E. Dahl-Jensen, I. Dahl-Jensen, P. Dam, G. Damgaard, A. Di Ciaccio, W. M. Evans, C. W. Fabjan, P. Frandsen, S. Frankel, W. Frati, M. Gibson, U. Goerlach, H. Gordon, K. H. Hansen, M. Harris, V. Hedberg, J. Hiddleston, G. Jarlskog, S. Katsanevas, T. Killian, R. Kroeger, K. Kulka, D. Lissauer, B. Lörstad, T. Ludlam, I. Mannelli, A. Markou, N. A. McCubbin, U. Mjörnmark, R. Møller, W. Molzon, A. Nappi, B. S. Nielsen, L. H. Olsen, Y. Oren, G. Pierrazzini, E. Rosso, A. Rudge, I. Stumer, M. Sullivan, J. A. Thompson, G. Thorstenson, E. Vella, J. Williamson, W. J. Willis, M. Winik, W. Witzeling, C. Woody, W. A. Zajc, and null (The Axial Field Spectrometer Collaboration)
- Subjects
Quark ,Physics ,Angular momentum ,Particle physics ,Meson ,High Energy Physics::Lattice ,High Energy Physics::Phenomenology ,Charged particle ,Gluon ,Momentum ,Nuclear physics ,Pion ,High Energy Physics::Experiment ,Rapidity ,Nuclear Experiment - Abstract
Rapidity and charge distributions have been measured for central charged tracks in events at center-of-mass energy 63 GeV, triggered on a ..pi../sup 0/ near 11/sup 0/ with transverse momentum greater than 2.25 GeV/c. The observed distributions are consistent with parton-parton scattering models with a spin-one gluon, and inconsistent with the exchange of a spin-zero gluon.
- Published
- 1985
331. A comparison of direct photon, π0 in p and pp interactions at the CERN ISR
- Author
-
K. Kulka, E. Vella, Ulf Mjörnmark, J. Lindsay, E. Rosso, Borge Svane Nielsen, H. Bøggild, M. D. Gibson, Alevtina Shmeleva, Yona Oren, K. H. Hansen, P. Dam, Christine Kourkoumelis, R. Carosi, Vincent Hedberg, E. Dahl-Jensen, T. Ludlam, P. W. Jeffreys, V. Sidorov, W. E. Cleland, C. L. Woody, Odette Benary, H. Specht, S. Katsanevas, C.W. Fabjan, W. Frati, J. W. Hiddleston, Torsten Paul Ake Åkesson, T. Jensen, S. Almehed, J. A. Thompson, Volker D. Burkert, A. Markou, W. A. Zajc, E. G. Anassontzis, G. Damgaard, S. Dagan, Ulrich Goerlach, Y. Choi, R. Kroeger, J. van der Lans, Richard Batley, W. J. Willis, Pavlos Ioannou, Boris Dolgoshein, R. Møller, Howard Gordon, Michael Albrow, I. Stumer, P. Frandsen, I. Dahl-Jensen, G. Thorstenson, V. Kantserov, P. Vasilev, G. Kesseler, A. Nilsson, H. Brody, A. Kalinovsky, A. A. Carter, W. Witzeling, G. Piskounov, T. Killian, L. H. Olsen, A. Rudge, Göran Jarlskog, W. R. Molzon, M.W. Evans, M. Winik, B. Lörstad, Yu. Golubkov, N. A. McCubbin, P. Nevsky, B. Callen, P.C. Cecil, D. Lissauer, Sherman Frankel, J. R. Carter, I. Gavrilenko, I. Mannelli, J. E. Hooper, S. Eidelman, Horst Breuker, S. Maiburov, V. Chernyatin, M. Sullivan, Robert B. Palmer, O. Botner, J.G. Williamson, L. K. Resvanis, Jurgen Schukraft, and D.C. Rahm
- Subjects
Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Particle physics ,Large Hadron Collider ,Photon ,Significant difference ,Rapidity - Abstract
We have measured the production of direct photons, π 0 's, and η's in p p and pp collisions at √ s =53 GeV in the range 2≈ p T ≈6 GeV/ c for the central rapidity region | y | 0.4. No statistically significant difference between pp and pp interactions is observed.
- Published
- 1985
332. A comparison of hadron production in and pp collisions in the central region at
- Author
-
J. v. d. Lans, W. M. Evans, I. Stumer, C.W. Fabjan, A. A. Carter, M. Sullivan, R. H. Schindler, M. D. Gibson, P. Frandsen, T. Killian, H. Bøggild, Göran Jarlskog, W. R. Molzon, M. Winik, P. Dam, E. Dahl-Jensen, W. A. Zajc, W. Witzeling, G. Thorstenson, Volker D. Burkert, P. Cecil, H. Hallgren, S. Dagan, B. Lörstad, D. Lissauer, T. Jensen, Torsten Paul Ake Åkesson, L. Rosselet, Sherman Frankel, Yona Oren, O. Botner, R. Kroeger, A. Markap, N.A. McCunnin, H. J. Hilke, P. W. Jeffreys, Odette Benary, R. Bartley, W. E. Cleland, W. Frati, J. W. Hiddleston, Vincent Hedberg, J. R. Carter, E. Rosso, C. L. Woody, W. J. Willis, I. Dahl-Jansen, Michael Albrow, S. Almehed, K. Kulka, J.G. Williamson, T. W. Ludlam, E. Vella, G. Damgaard, J. E. Hooper, Horst Breuker, Borge Svane Nielsen, Ulf Mjörnmark, K. H. Hansen, Ulrich Goerlach, J. Lindsay, Howard Gordon, Anders Nilsson, H. Brody, L. H. Olsen, A. Rudge, David Ja Cockerill, and R. Møller
- Subjects
Baryon ,Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Pair production ,Proton ,Hadron ,Production (computer science) ,Atomic physics ,Lambda ,Positive correlation ,Central region - Abstract
We have studied the inclusive production of the hadrons π±, K±, p, p , Λ, Λ , ρ and ⋉ in the central region at the ISR s = 53 GeV , in both pp and p p collisions. Differences are observed only for K±, p, and p production. We then study also correlations between low-pT pp and p p pairs in the two types of collisions, separating the contribution from baryon pair production and from the incident particles (stopping protons). We observe a positive correlation between two stopping protons; between the production of two pairs, and between a stopping proton and a pair production, there are negative correlations.
- Published
- 1983
333. Results from the BNL E802 spectrometer for 14.5 GeV/c per nucleon silicon beams
- Author
-
L. Birstein, J. Engelage, F. Videbaek, D. S. Woodruff, R. R. Debbe, V. Vutsadakis, R. J. Ledoux, R. J. Morse, H. Hamagaki, Russell Richard Betts, Lee Grodzins, K. Kitamura, E. Duek, Y. Akiba, M. J. LeVine, S. Hayashi, J. B. Cumming, C. Chasman, S. Homma, C. G. Parsons, M. J. Tannenbaum, David E. Alburger, S. Gushue, M. Torikosh, G. S. F. Stephans, P. D. Bond, H. J. Crawford, H. Z. Huang, P. Stankus, Yasuo Miake, S. Nagamiya, S. B. Kaufman, Ma Bloomer, W. A. Zajc, W. A. Watson, Brian Cole, Yuichi Ikeda, Y. Y. Chu, M. Vient, L. P. Remsber, K. Kurita, O. Hansen, J. B. Costales, M. Sarabura, J. H. van Dijk, H. E. Wegner, K. Kimura, T. Abbott, P. Vincent, A. Shor, Y. D. Wu, M. Tanaka, S. Katcoff, S. G. Steadman, S. Y. Fung, Toru Sugitate, D. R. Beavis, and J.W. Olness
- Subjects
Physics ,Nuclear reaction ,Nuclear and High Energy Physics ,Proton ,Spectrometer ,Nuclear Theory ,Charged particle ,Particle identification ,Spectral line ,Nuclear physics ,Deuterium ,High Energy Physics::Experiment ,Atomic physics ,Nuclear Experiment ,Nucleon - Abstract
We present selected results of measurements of inclusive ..pi.., K, proton, and deuteron spectra from 14.5 A GeV/c Si collisions with various targets. Results of neutral energy and charged particle dN/d/eta/ measurements are also discussed. Large K to ..pi.. ratios are observed in Si + Au collisions. Results are compared to the Lund-Fritiof model. 11 refs., 11 figs.
- Published
- 1989
334. Bose-Einstein correlations in αα, pp and interactions
- Author
-
L. H. Olsen, A. Markou, H. J. Hilke, David Ja Cockerill, J. van der Lans, R. Batley, R. Møller, Odette Benary, I. Dahl-Jensen, Howard Gordon, M. Sullivan, G. Kesseler, P. Cecil, S. Almehed, W. M. Evans, A. Kalinovsky, T. Killian, P. Frandsen, P. Dam, S. Dagan, W. R. Molzon, M. Winik, K. Kulka, R. H. Schindler, Göran Jarlskog, W. J. Willis, E. Vella, C.W. Fabjan, G. Damgaard, Michael Albrow, Ulrich Goerlach, B. Lörstad, Ulf Mjörnmark, Volker D. Burkert, N. A. McCubbin, H. Brody, Yona Oren, C. L. Woody, J. Lindsay, J. R. Carter, Vincent Hedberg, T. Ludlam, E. Rosso, W. Frati, J. W. Hiddleston, A. Rudge, W. A. Zajc, S. U. Chung, D. Lissauer, Anders Nilsson, P. Jeffreys, W. Cleland, Sherman Frankel, B. W. Heck, Horst Breuker, Borge Svane Nielsen, J.G. Williamson, K. H. Hansen, R. Kroeger, W. Witzeling, M. D. Gibson, Torsten Paul Ake Åkesson, L. Rosselet, A. A. Carter, S. Eidelman, E. Dahl-Jensen, O. Botner, H. Bøggild, J. E. Hooper, and G. Thorstenson
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,chemistry.chemical_element ,Bose–Einstein correlations ,High multiplicity ,Central region ,Nuclear physics ,Particle type ,Pion ,chemistry ,Rapidity ,Multiplicity (chemistry) ,Helium - Abstract
Bose-Einstein correlations between pions produced in the central region of rapidity in αα, pp and p p interactions have been studied at the ISR. The parameters r and τ c -often interpreted as the radius and depth of the π-emitting region - are found to be independent of incident particle type but to depend on the mean charged multiplicity. In high multiplicity events, the pions appear to originate from a larger space-time region.
- Published
- 1983
335. The dominance of jets at large transverse energy in a full-azimuth hadron calorimeter at ISR energies
- Author
-
M. Sullivan, P. Frandsen, S. Dagan, A. A. Carter, R. Carosi, Torsten Paul Ake Åkesson, L. Rosselet, O. Botner, G. Damgaard, G. Thorstenson, Howard Gordon, W. A. Zajc, C. W. Fabjan, S. Almehed, M. D. Gibson, I. Dahl-Jensen, W. J. Willis, P. Jeffreys, Michael Albrow, Ulrich Goerlach, A. Hallgren, T. Ludlam, J. E. Hooper, J. v. d. Lans, S. U. Chung, W. Cleland, Richard Batley, Odette Benary, E. Dahl-Jensen, B. Lörstad, D. Lissauer, W. M. Evans, H. Bøggild, I. Stumer, R. H. Schindler, J. R. Carter, Horst Breuker, Göran Jarlskog, C. L. Woody, W. Frati, J. W. Hiddleston, K. H. Hansen, Anders Nilsson, H. J. Hilke, A. Kalinovsky, S. Eidelman, T. Killian, W. R. Molzon, T. Jensen, M. Winik, R. Kroeger, W. Witzeling, H. Brody, G. Kesseler, P. Cecil, A. Markou, J. G. Williamson, Vincent Hedberg, B. W. Heck, E. Rosso, K. Kulka, E. Vella, Ulf Mjörnmark, J. Lindsay, N. A. McCubbin, Sherman Frankel, L. H. Olsen, P. Dam, David Ja Cockerill, R. Møller, Volker D. Burkert, Yona Oren, Borge Svane Nielsen, and A. Rudge
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,Meson ,Calorimeter (particle physics) ,Physics::Instrumentation and Detectors ,Hadron ,Elementary particle ,Azimuth ,Nuclear physics ,Transverse plane ,Pion ,Antimatter ,High Energy Physics::Experiment ,Computer Science::Symbolic Computation ,Nuclear Experiment ,Particle Physics - Experiment ,Computer Science::Distributed, Parallel, and Cluster Computing - Abstract
Events with a large transverse energy in a calorimeter with full azimuthal coverage and |y
- Published
- 1983
336. Orbital Recoupling Dominance in theA=20Isovector GiantM1Transition
- Author
-
S. S. Rosenblum, G. Strassner, J. P. Miller, Kenneth M. Crowe, James A. Bistirlich, Helmut W. Baer, C. J. Martoff, Masahiro Koike, P. Truöl, W. A. Zajc, and A. H. Wapstra
- Subjects
Physics ,Nuclear reaction ,Amplitude ,Isovector ,Branching fraction ,Giant resonance ,General Physics and Astronomy ,Spin-flip ,Atomic physics ,Orbital magnetization ,Spectral line - Abstract
The photon spectrum from /sup 20/Ne(0/sup -/,..gamma..)/sup 20/F has been measured. The branching ratio to /sup 20/F(1/sup +/,1.06 MeV) is compared to the analogous M1 decay width /sup 20/Ne(1/sup +/,11.24 MeV)..-->../sup 20/Ne(g.s.). This determines the relative importance of spin and orbital magnetization in the transition amplitude. The M1 amplitude is found to contain only (47 +- 16)% spin flip, in agreement with shell-model calculations. Excitation of 2/sup -/ states by /sup 20/Ne(..pi../sup -/,..gamma..) is also observed.
- Published
- 1981
337. Properties of jets in high-E T events produced inpp collisions at $$\sqrt s $$ =63 GeV
- Author
-
Odette Benary, N. A. McCubbin, Yona Oren, D. Lissauer, Sherman Frankel, J. R. Carter, P. Cecil, G. Damgaard, H. J. Specht, Y. Choi, Torsten Paul Ake Åkesson, L. Rosselet, O. Botner, Borge Svane Nielsen, L. H. Olsen, Ulrich Goerlach, W. Frati, J. W. Hiddleston, David Ja Cockerill, J. v. d. Lans, Richard Batley, R. Møller, C.W. Fabjan, G. Thorstenson, M. D. Gibson, W. M. Evans, I. Stumer, I. Dahl-Jensen, Horst Breuker, J.G. Williamson, E. Dahl-Jensen, P. Frandsen, W. Witzeling, K. H. Hansen, A. Rudge, U. Mjörnmark, V. Burkert, Vincent Hedberg, E. Rosso, S. Dagan, J. E. Hooper, G. Kesseler, R. Carosi, B. Lörstad, P. Jeffreys, K. Kulka, E. Vella, R. Kroeger, W. J. Willis, Anders Nilsson, B. Callen, S. Eidelman, Michael Albrow, C. L. Woody, P. Dam, J. Lindsay, T. W. Ludlam, S. Almehed, J. A. Thompson, T. Jensen, W. A. Zajc, A. Markou, M. Sullivan, H. Brody, Howard Gordon, A. Kalinovsky, R. H. Schindler, Göran Jarlskog, A. A. Carter, T. Killian, H. Bøggild, W. R. Molzon, W. E. Cleland, M. Winik, and H. J. Hilke
- Subjects
Quark ,Physics ,Particle physics ,Annihilation ,Large Hadron Collider ,Physics and Astronomy (miscellaneous) ,Intersecting Storage Rings ,Astrophysics::High Energy Astrophysical Phenomena ,Elementary particle ,Charged particle ,Gluon ,Nuclear physics ,Particle acceleration ,High Energy Physics::Experiment ,Nuclear Experiment ,Engineering (miscellaneous) - Abstract
The properties of high-ET events produced inpp collisions at\(\sqrt s \)=63 GeV have been studied at the CERN Intersecting Storage Rings. The fragmentation of the jets is found to be very similar to that of jets produced ine+e− annihilation and at the SPS\(p\bar p\) collider. We measure an excess of soft particles compared withe+e− events and this underlying event is found to be sensitive to the trigger. ThepT balance between the jets is measured. The distribution of charges in the jets indicates that a substantial fraction of the jets originate from valence quarks.
- Published
- 1984
338. Spin flip transitions inC13andF19probed with the (π−, γ) reaction
- Author
-
M. Koike, C. W. Clawson, James A. Bistirlich, Kenneth M. Crowe, Helmut W. Baer, S. S. Rosenblum, J. P. Miller, G. Strassner, C. J. Martoff, A. H. Wapstra, P. Truöl, and W. A. Zajc
- Subjects
Nuclear reaction ,Physics ,Nuclear and High Energy Physics ,Pion ,Branching fraction ,Neutron ,Isotopes of boron ,Spin-flip ,Atomic physics ,Nucleon ,Beta decay - Abstract
Photon spectra from radiative capture of stopped negative pions captured by /sup 13/C and /sup 19/F nuclei have been measured with a high resolution pair spectrometer. In the bound region transitions have been observed to /sup 13/B(g.s.), /sup 13/B(3.5 MeV), /sup 19/O(g.s.), /sup 19/O(4.9 MeV), and /sup 19/O(6.3 MeV). In addition, strong transitions to narrow states above the neutron separation threshold were observed in both cases. The results for /sup 13/C are in agreement with detailed shell model calculations of this process. Major strength is observed for states formed by coupling extra nucleons or holes to the spin-quadrupole d/sub 5/2/ and d/sub 3/2/, J/sup ..pi../ = 2/sup -/ states in /sup 16/O. The /sup 13/C(..pi../sup -/,..gamma..)/sup 13/B/sub g.s./ branching ratio is shown to be consistent with beta decay and electroexcitation data, through a combined phenomenological analysis. The observed transition strengths are accounted for by matrix elements of the spin-density operators (sigma x Y/sub 0/)/sup 1/t/sup +/ and (sigma x Y/sub 1/)t/sup +/.
- Published
- 1983
339. A study of the production of two direct photons inpp collisions at the CERN ISR
- Author
-
E. G. Anassontzis, G. Damgaard, H. J. Specht, Odette Benary, Y. Choi, P. Vasiliev, C. L. Woody, S. Eidelman, Ulrich Goerlach, B. Callen, S. Almehed, Richard Batley, Torsten Paul Ake Åkesson, J. A. Thompson, I. Dahl-Jensen, I. Mannelli, W. J. Willis, O. Botner, R. Kroeger, M. Sullivan, S. Katsanevas, C.W. Fabjan, S. Dagan, K. Kulka, Vincent Hedberg, P. Dam, Michael Albrow, G. Piskounov, Volker D. Burkert, W. M. Evans, Yona Oren, I. Stumer, V. Sidorov, V. Kantserov, E. Vella, Ulf Mjörnmark, B. Lörstad, I. Gavrilenko, P. Cecil, W. Frati, J. W. Hiddleston, T. Jensen, A. Markou, R. Carosi, G. Thorstenson, Christine Kourkoumelis, E. Dahl-Jensen, Borge Svane Nielsen, Horst Breuker, Alevtina Shmeleva, W. A. Zajc, N. A. McCubbin, A. Rudge, K. H. Hansen, Y. Goloubdov, D. Lissauer, Sherman Frankel, A. Kalinovsky, J. R. Carter, A. A. Carter, H. Bøggild, S. Mayburov, W. R. Molzon, P. Nevsky, J.G. Williamson, L. K. Resvanis, Jurgen Schukraft, Boris Dolgoshein, R. Møller, L. H. Olsen, V. Chernyatin, Göran Jarlskog, Howard Gordon, and W. E. Cleland
- Subjects
Physics ,Particle physics ,Photon ,Large Hadron Collider ,Physics and Astronomy (miscellaneous) ,Astrophysics::High Energy Astrophysical Phenomena ,Elementary particle ,Nuclear physics ,Transverse momentum ,High Energy Physics::Experiment ,Rapidity ,Production (computer science) ,Nuclear Experiment ,Engineering (miscellaneous) ,Particle Physics - Experiment - Abstract
We have studied the processpp→γγ+X at\(\sqrt s = 63 GeV\) GeV in the central rapidity region. We report a positive signal at 96% C.L., a ratio γγ/e+e−=4.0±3.0 when the transverse momentum of each photon is above 2 GeV/c, and a cross-sectiondσ/dydMγγ=(5.5±2.7)×10−34 cm2/GeV when |y
- Published
- 1986
340. ptandEtmultiplicity correlations inp−p,p−α, andα−αinteractions ats=31.5 and 44GeV
- Author
-
J. v. d. Lans, W. M. Evans, I. Stumer, P. Frandsen, B. W. Heck, Anders Nilsson, R. Møller, E. Dahl-Jensen, B. Schistad, L. Rosselet, L. H. Olsen, David Ja Cockerill, I. Dahl-Jensen, K. H. Hansen, H. Bøggild, W. R. Molzon, M. Winik, R. H. Schindler, Göran Jarlskog, N. A. McCubbin, D. Lissauer, T. Jensen, S. Dagan, W. Witzeling, W. A. Zajc, Olga Botner, Borge Svane Nielsen, Sherman Frankel, E. Vella, B. Lörstad, P. W. Jeffreys, Howard Gordon, A. Rudge, W. J. Willis, Michael Albrow, M. Wood, T. W. Ludlam, Odette Benary, C.W. Fabjan, Ulf Mjörnmark, W. Frati, G. Kesseler, Volker D. Burkert, Yona Oren, T. Killian, E. Rosso, C. L. Woody, S. Almehed, J. E. Hooper, G. Damgaard, H. Brody, T. P. A. Åkesson, and H. J. Hilke
- Subjects
Nuclear physics ,Physics ,Nuclear reaction ,Particle physics ,Particle properties ,chemistry ,Transverse momentum ,chemistry.chemical_element ,Multiplicity (mathematics) ,Helium - Abstract
Measurements of the central multiplicity associated with high-p/sub t/ particles up to 2 GeV/c in p-p, p-..cap alpha.., and ..cap alpha..-..cap alpha.. collisions, and measurements of dsigma/dE/sub t/ are presented. The difference in associated multiplicity, n(p-..cap alpha..)-n(p-p), is independent of p/sub t/ while n(..cap alpha..-..cap alpha..)-n(p-p) rises with p/sub t/, providing new information on the ''anomalous'' p/sub t/ dependence of nuclear inclusive cross sections.
- Published
- 1983
341. A measurement of alpha-alpha elastic scattering at the CERN ISR
- Author
-
L. H. Olsen, D. Weygand, Torsten Paul Ake Åkesson, K. Kulka, H. Bøggild, O. Botner, David Ja Cockerill, R. Møller, M. Sullivan, W. J. Willis, D. Lissauer, Vincent Hedberg, Michael Albrow, J. van der Lans, C.W. Fabjan, W. M. Evans, B. Lörstad, A. Rudge, I. Stumer, Horst Breuker, S. Almehed, E. Vella, S. Dagan, K. H. Hansen, P. Frandsen, I. Dahl-Jensen, J. R. Carter, J. A. Thompson, T. W. Ludlam, Sherman Frankel, Ulrich Goerlach, J. Lindsay, J. G. Williamson, A. A. Carter, Richard Batley, P. Dam, J. E. Hooper, W. A. Zajc, M. J. Goodrick, T. W. Pritchard, H. Brody, Borge Svane Nielsen, G. Damgaard, C. L. Woody, W. Frati, J. W. Hiddleston, R. Kroeger, P. Cecil, Yona Oren, G. Thorstenson, Odette Benary, M. D. Gibson, E. Dahl-Jensen, W. Cleland, S. U. Chung, Göran Jarlskog, Howard Gordon, W. R. Molzon, M. Winik, and N. A. McCubbin
- Subjects
Nuclear reaction ,Elastic scattering ,Physics ,Nuclear and High Energy Physics ,Range (particle radiation) ,Particle physics ,Scattering ,Extrapolation ,Alpha particle ,Charged particle ,Nuclear physics ,Cross section (physics) ,Nuclear Experiment ,Particle Physics - Experiment - Abstract
We present measurements of the αα elastic scattering differential cross section at √ s = 126 GeV in the range 0.05 ⩽ ‖ t ‖ c ) 2 . The data give an improved definition of the first cross section minimum at ‖ t ‖ = 0.098 (GeV/ c ) 2 and are consistent with theotheoretical models of nucleus-nucleus scattering. The αα total cross section obtained by extrapolation to the optical point is 280 ± 70 mb.
- Published
- 1985
342. Dijet production cross-section and fragmentation of jets produced in pp collisions at $\sqrt{s}$ = 63 GeV
- Author
-
K. Kulka, E. Vella, Ulf Mjörnmark, Yona Oren, Jurgen Schukraft, G. Damgaard, H. J. Specht, Y. Choi, B. Lörstad, G. Thorstenson, I. Dahl-Jensen, W. J. Willis, I. Stumer, Odette Benary, Michael Albrow, R. Møller, K. H. Hansen, Borge Svane Nielsen, Vincent Hedberg, C. L. Woody, A. A. Carter, J.G. Williamson, Horst Breuker, E. Dahl-Jensen, S. Almehed, J. A. Thompson, S. Dagan, S. Katsanevas, C.W. Fabjan, R. Kroeger, N. A. McCubbin, D. Lissauer, Sherman Frankel, Torsten Paul Ake Åkesson, L. Rosselet, W. A. Zajc, J. R. Carter, H. Bøggild, B. Callen, P. Cecil, H. H. Thodberg, Ulrich Goerlach, Richard Batley, W. E. Cleland, Howard Gordon, L. H. Olsen, W. Frati, Göran Jarlskog, A. Markou, M. Sullivan, and O. Botner
- Subjects
Quark ,Physics ,Particle physics ,Large Hadron Collider ,Physics and Astronomy (miscellaneous) ,Intersecting Storage Rings ,Astrophysics::High Energy Astrophysical Phenomena ,Solid angle ,Charge density ,Super Proton Synchrotron ,Nuclear physics ,Transverse plane ,Fragmentation (mass spectrometry) ,High Energy Physics::Experiment ,Nuclear Experiment ,Engineering (miscellaneous) ,Particle Physics - Experiment - Abstract
We present stdies of events triggered on two high-pT jets, produced inpp collisions at the CERN Intersecting Storage Rings (ISR) at\(\sqrt s \)=63 GeV, using a large solid angle calorimeter. The cross-section for producing two jets is measured in the dijet mass range 17–50 GeV/c2. A high-statistics sample of dijet events, where each jet has transverse energy above 10 GeV, is used to study the structure of jets and the associated event. We find the longitudinal fragmentation function to be similar to that of jets emerging frome+e− collisions but considerably harder than that observed at the Super Proton Synchrotron (SPS)\(p\bar p\) Collider. A steepening of the fragmentation function is observed when increasing the jet energy. Studies of the charge distribution in jets show that these predominantly originate from fragmenting valence quarks. The transverse energy and particle flows are presented as functions of the azimuthal distance from the jet axis.
- Published
- 1985
343. Evidence for a directional dependence of Bose-Einstein correlations at the CERN Intersecting Storage Rings
- Author
-
B. Lörstad, K. Kulka, C.W. Fabjan, E. Vella, R. Kroeger, J. R. Carter, G. Jarlskog, Yona Oren, W. R. Molzon, Ulf Mjörnmark, Torsten Paul Ake Åkesson, J.G. Williamson, S. Almehed, S. Dagan, M. Sullivan, K. H. Hansen, O. Benary, N. A. McCubbin, W. A. Zajc, L. Olsen, A. Markou, A. A. Carter, Borge Svane Nielsen, R. Møller, M.G. Albrow, E. Dahl-Jensen, W. E. Cleland, V. Hedberg, H. Bøggild, D. Lissauer, G. Damgaard, O. Botner, V. Burkert, Horst Breuker, W. J. Willis, J. A. Thompson, Ulrich Goerlach, I. Stumer, and I. Dahl-Jensen
- Subjects
Physics ,Nuclear and High Energy Physics ,Intersecting Storage Rings ,Elementary particle ,Bose–Einstein correlations ,Charged particle ,Nuclear physics ,symbols.namesake ,Pion ,Bose–Einstein statistics ,Antimatter ,symbols ,Atomic physics ,Nuclear Experiment ,Beam (structure) ,Particle Physics - Experiment - Abstract
In pp and pp collisions at the CERN Intersecting Storage Rings, a directional dependence of the size of the pion-emitting region is observed using Bose-Einstein interference between identical charged pions. The data reveal a substantially larger dimension in the direction parallel to the beam axis than in the transverse direction, indicating a prolate shape of the emission region. For αα interactions, the data are consistent with a spherical shape.
- Published
- 1986
344. Pion production near mid-rapidity in high-energy heavy-ion collisions
- Author
-
M. Koike, R. Bossingham, Jr. Nolen, J. P. Sullivan, H. R. Bowman, J. P. Miller, E. Kashy, O. Hashimoto, James A. Bistirlich, E. Yoo, C. J. Martoff, D. L. Murphy, Jean Péter, K.A. Frankel, Kenneth M. Crowe, John O. Rasmussen, G.M. Crawley, J. Québert, W. Benenson, and W. A. Zajc
- Subjects
Nuclear reaction ,Physics ,Nuclear physics ,Nuclear and High Energy Physics ,Pion ,Meson ,Electric field ,Hadron ,Elementary particle ,Rapidity ,Center of mass - Abstract
Doubly differential cross sections for producing ..pi../sup +/ and ..pi../sup -/ were measured for several target-projectile combinations. They were /sup 40/Ar+C, Ca, and U at 1050A MeV and /sup 20/Ne+Be and NaF at 655A MeV. The ..pi../sup -//..pi../sup +/ ratios are smaller than those expected from several Coulomb effect calculations. The Ne+NaF..--> pi../sup -/ data exhibit a peak at 90/sup 0/ in the center of mass and p/sub ..pi../ = 0.4m/sub ..pi../c.
- Published
- 1985
345. Spectrometer results from BNL E802
- Author
-
J. Engelage, M. Sarabura, H. E. Wegner, Hiroyoshi Sakurai, S. Katcoff, P. W. Stankus, Hideki Hamagaki, R. J. Morse, J. B. Cumming, Russell Richard Betts, E. Duek, R. R. Debbe, L. Birstein, J.W. Olness, F. Videbæk, H. Z. Huang, Brian Cole, S. G. Steadman, David E. Alburger, S. Gushue, W. A. Watson, M. J. LeVine, J. B. Costales, S. Homma, George Stephans, K. Kurita, S. B. Kaufman, D. S. Woodruff, Lee Grodzins, M. J. Tannenbaum, C. Chasman, M. Tanaka, Ryugo S. Hayano, M. Vient, W. A. Zajc, R. J. Ledoux, Yuichi Ikeda, S. Y. Fung, P. Vincent, T. Abbott, H. J. Crawford, K. Kitamura, Y. Y. Chu, A. Shor, V. Vutsadakis, C. G. Parsons, Toru Sugitate, P. D. Bond, K. Kimura, D. R. Beavis, J. H. van Dijk, Shinichi Hayashi, L. P. Remsberg, M. Torikoshi, Ole Hansen, Yang Wu, Y. Akiba, S. Nagamiya, Yasuo Miake, and Ma Bloomer
- Subjects
Physics ,Nuclear reaction ,Particle physics ,Meson ,Spectrometer ,Physics::Instrumentation and Detectors ,Nuclear Theory ,Hadron ,Fermion ,Baryon ,Nuclear physics ,High Energy Physics::Experiment ,Spallation ,Nuclear Experiment ,Nucleon - Abstract
Measurements of collisions of 14.5 GeV/c per nucleon 28Si ions with nuclear targets using the BNL E802 spectrometer are presented. A description of the experiment and preliminary particle ratios are discussed.
- Published
- 1988
346. A search for glueballs and a study of double pomeron exchange at the CERN Intersecting Storage Rings
- Author
-
David Ja Cockerill, Odette Benary, Torsten Paul Ake Åkesson, L. Rosselet, Sherman Frankel, O. Botner, J. v. d. Lans, R. Møller, J.G. Williamson, W. M. Evans, I. Stumer, S. Almehed, Borge Svane Nielsen, J. A. Thompson, P. Frandsen, Vincent Hedberg, W. A. Zajc, M. J. Goodrick, A. A. Carter, R. Carosi, A. Rudge, W. Cleland, G. Thorstenson, Y. Oren, A. Markou, M. Sullivan, G. Damgaard, S. Dagan, L. H. Olsen, I. Dahl-Jensen, W. J. Willis, Michael Albrow, N. A. McCubbin, T. W. Ludlam, Göran Jarlskog, E. Rosso, M. D. Gibson, H. J. Hilke, T. W. Pritchard, P. Cecil, K. Kulka, E. Vella, Ulf Mjörnmark, P. Dam, S. U. Chung, E. Dahl-Jensen, J. Lindsay, C. L. Woody, D. Lissauer, W. Frati, J. W. Hiddleston, R. Kroeger, W. Witzeling, Horst Breuker, H. Bøggild, K. H. Hansen, B. Lörstad, C.W. Fabjan, Volker D. Burkert, J. R. Carter, T. Killian, Anders Nilsson, W. R. Molzon, M. Winik, Ulrich Goerlach, Richard Batley, and D. Weygand
- Subjects
Physics ,Nuclear and High Energy Physics ,Particle physics ,Large Hadron Collider ,Meson ,Intersecting Storage Rings ,Partial wave analysis ,Scalar (mathematics) ,Resonance (chemistry) ,Nuclear physics ,Pomeron ,Mass spectrum ,High Energy Physics::Experiment ,Nuclear Experiment ,Particle Physics - Experiment - Abstract
We present results from a study of centrally produced mesons in 3 × 106 events with two small-angle protons at the CERN Intersecting Storage Rings. A high-statistics sample of exclusive pp → ppπ+π− events at √s = 63 GeV has been obtained, where the reaction mechanism is dominated by double pomeron exchange. Scalar or tensor glueballs may be produced by this process. The π+π− mass spectrum has a distinctive structure, and analysis shows that the data are dominantly S-wave up to 1600 MeV. The behaviour of the D-wave provides evidence for a 2++ resonance (M = 1480 ± 50 MeV, Γ = 150 ± 50 MeV) in addition to the f(1270). We also show data on exclusive K + K − , p p , and π + π − π + π − production, and on the analogous reaction αα → ααπ+π− at √s = 126 GeV. Flavour independence is suggested by the observation of approximately equal numbers of K+K− and π+π− pairs for mass above 1 GeV. The mass spectra are also apparently independent of √s (45, 63, 126 GeV) and incident particle type (p, α).
- Published
- 1985
347. Two-pion correlations in heavy ion collisions
- Author
-
W. A. Zajc
- Subjects
Nuclear physics ,Physics ,Correlation function (statistical mechanics) ,symbols.namesake ,Pion ,Meson ,Bose–Einstein statistics ,Hadron ,Monte Carlo method ,symbols ,Elementary particle ,Nuclear Experiment ,Boson - Abstract
An application of intensity interferometry to relativistic heavy ion collisions is reported. Specifically, the correlation between two like-charged pions is used to study the reactions Ar+KCl..-->..2..pi../sup +-/+X and Ne+NaF..-->..2..pi../sup -/+X. Source sizes are obtained that are consistent with a simple geometric interpretation. Lifetimes are less well determined but are indicative of a faster pion production process than predicted by Monte Carlo cascade calculations. There appears to be a substantial coherent component of the pion source, although measurement is complicated by the presence of final state interactions. Additionally, the generation of spectra of uncorrelated events is discussed. In particular, the influence of the correlation function on the background spectrum is analyzed, and a prescription for removal of this influence is given. A formulation to describe the statistical errors in the background is also presented. Finally, drawing from the available literature, a self-contained introduction to Bose-Einstein correlations and the Hanbury-Brown - Twiss effect is provided, with an emphasis on points of contact between classical and quantum mechanical descriptions.
- Published
- 1982
348. BOSE-EINSTEIN CORRELATIONS: FROM STATISTICS TO DYNAMICS
- Author
-
W. A. Zajc
- Subjects
Physics ,Dynamics (mechanics) ,Bose–Einstein correlations ,Mathematical physics - Published
- 1988
349. A study of exclusive central hadron production at the ISR as a search for gluonium states
- Author
-
M. D. Gibson, W. A. Zajc, M. J. Goodrick, E. Dahl-Jensen, W. J. Willis, H. Bøggild, Michael Albrow, H. J. Hilke, G. Thorstenson, J. v. d. Lans, J.G. Williamson, P. Jeffreys, W. M. Evans, R. Kroeger, I. Stumer, P. Dam, W. Witzeling, P. Frandsen, T. W. Pritchard, P. Cecil, Vincent Hedberg, A. A. Carter, R. Carosi, S. Dagan, B. Lörstad, L. H. Olsen, M. Sullivan, David Ja Cockerill, G. Damgaard, J. R. Carter, R. Møller, N. A. McCubbin, Borge Svane Nielsen, Sherman Frankel, A. Rudge, Torsten Paul Ake Åkesson, L. Rosselet, H. Brody, O. Botner, S. Almehed, J. E. Hooper, Yona Oren, J. A. Thompson, W. Cleland, Odette Benary, T. Ludlam, Anders Nilsson, C.W. Fabjan, Volker D. Burkert, D. Lissauer, Ulrich Goerlach, Richard Batley, Horst Breuker, I. Dahl-Jensen, K. H. Hansen, C. L. Woody, W. Frati, J. W. Hiddleston, D. Weygand, G. Kesseler, A. Markou, E. Rosso, K. Kulka, E. Vella, Ulf Mjörnmark, J. Lindsay, T. Killian, W. R. Molzon, M. Winik, Howard Gordon, R. H. Schindler, Göran Jarlskog, and S. U. Chung
- Subjects
Physics ,Nuclear physics ,Baryon ,Nuclear and High Energy Physics ,Antiparticle ,Particle physics ,Pion ,Pair production ,Meson ,Antimatter ,Hadron ,Nucleon ,Particle Physics - Experiment - Abstract
We present first results from a study of the exclusive reaction pp→pπ+π−p at √s=63 GeV with π+ and π− produced in the central region. This reaction has been suggested as a method of searching for gluonium states. The π+π− mass distribution shows rapid order of magnitude decreases in cross section at both 1000 MeV/c2 and 1500 MeV/c2. Further structure is observed above 2000 MeV/c2.
- Published
- 1983
350. Monte Carlo calculational methods for the generation of events with Bose-Einstein correlations
- Author
-
W. A. Zajc
- Subjects
Physics ,Hybrid Monte Carlo ,symbols.namesake ,Metropolis–Hastings algorithm ,Bose–Einstein statistics ,Quantum electrodynamics ,Monte Carlo method ,Dynamic Monte Carlo method ,symbols ,Context (language use) ,Bose–Einstein correlations ,Statistical physics ,Wave function - Abstract
The momentum-space correlations for n bosons emitted by a source distributed in space and time are discussed in the context of intensity interferometry for identical pions. The Metropolis algorithm is used to generate events containing such correlations to all orders via a Monte Carlo technique. Direct calculation of the probability for multiparticle correlations is practicable for n-body states up to n\ensuremath{\sim}20. Beyond this, a method which samples the symmetrized n-body probability must be used. It is observed that the traditional pair-correlation function is distorted for events with high phase-space density in a fashion consistent with the results of a simple model calculation.
- Published
- 1987
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