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1. Strangeness production in Au + Au collisions at AGS energies

Author

Eun Jin Kim, H. Wang, Russell Richard Betts, A. H. Wuosmaa, Youngil Kwon, H. B. Yao, David Jonathan Hofman, Y. Y. Chu, B. B. Back, A. Gillitzer, C. Y. Chi, C. M. Zou, S. Y. Kim, Ju Hwan Kang, W. C. Chang, Alice Mignerey, Burt Holzman, George Stephans, J. Stanskas, W. Eldredge, D. E. Russ, V. Nanal, D. McLeod, R. Ganz, F. L. H. Wolfs, M. Moulson, E. Garcia, R. Seto, J. B. Cumming, G. H. Xu, A. Ruangma, J. C. Dunlop, R. Pak, S. Y. Fung, C. A. Ogilvie, W. F. Henning, B.B. Back, G. Heintzelman, H. Xiang, and J. Chang

Subjects
Physics, Nuclear and High Energy Physics, Proton, Strangeness production, Kinetic energy, Spectral line, Momentum, Nuclear physics, Physics::Accelerator Physics, Rapidity, Atomic physics, Nuclear Experiment, Nucleon, Beam (structure)
Abstract

Collisions of Au + Au have been studied at beam kinetic energies of 6.0, 8.0 and 10.8 GeV/nucleon at the AGS facility at Brookhaven National Laboratory. Particles emitted from the collisions were momentum analysed and identified in a magnetic spectrometer. Proton rapidity distributions are compared with those expected for isotropic emission from a stopped source and it is concluded that there is a substantial amount of transparency at all three beam energies even for the most central collisions. Strangeness production were studied via measurements of K, and spectra. All three indicate a strong enhancement of strangeness production relative to pp-collisions at similar centre-of-mass energies.

Published
2001
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2. Results from experiment E917 for Au + Au collisions at the AGS

Author

G. Heintzelman, Youngil Kwon, W. F. Henning, D. McLeod, J. C. Dunlop, Burt Holzman, H. Xiang, E.-J. Kim, G. H. Xu, A. H. Wuosmaa, C. Y. Chi, D. Russ, B. B. Back, M. Moulson, S. Y. Fung, George Stephans, Russell Richard Betts, W. Eldredge, D. J. Hofman, A. Gillitzer, E. Garcia, J. B. Cumming, H. B. Yao, R. Seto, F.L.H. Wolfs, C. A. Ogilvie, R. Ganz, Alice Mignerey, P. J. Stanskas, V. Nanal, H. Wang, Y. Y. Chu, R. Pak, W. C. Chang, Ju Hwan Kang, A. Ruangma, C. M. Zou, S. Y. Kim, and J. Chang

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Nuclear Theory, Hadron, Strangeness, Lambda baryon, Baryon, Nuclear physics, Antiproton, Antimatter, Stopping power (particle radiation), Nuclear Experiment, Nucleon
Abstract

The effects of baryon stopping and its resulting energy deposition on the dynamics of Au + Au collisions at 6, 8 and 10.8 GeV/nucleon are explored with recent results from the AGS experiment E917. Current analyses of stopping, collective flow signals and HBT parameters are presented. Strangeness and anti-baryon production is examined using the yields of anti-lambdas and anti-protons.

Published
1999
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3. The PHENIX Multiplicity and Vertex Detector

Author

George Davey Smith, C. Y. Soon, Yongsun Kim, T. Shiina, S. F. Hahn, M. J. Bennett, R. Cunningham, Yoshiyuki Takahashi, J. Chang, Milton Nance Ericson, L. J. Marek, Jae-Suk Park, G. H. Xu, Sewha Kim, R. Conway, Miljko Bobrek, J. H. Kang, B. R. Schlei, J. P. Sullivan, J. G. Boissevain, H. W. Van Hecke, C.L. Britton, M.S. Emery, D. Jaffe, J. Simon-Gillo, G. Richardson, S. Y. Fung, J.A. Moore, and S. S. Ryu

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Physics::Instrumentation and Detectors, High Energy Physics::Experiment, Vertex detector, Multiplicity (chemistry), PHENIX detector, Nuclear Experiment, Relativistic Heavy Ion Collider
Abstract

We describe the design and expected performance of the PHENIX Multiplicity and Vertex Detector (MVD) sub-system of the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC).

Published
1999
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4. Simultaneous multiplicity and forward energy characterization of particle spectra in Au+Au collisions at11.6AGeV/c

Author

J.W. Olness, Alice Mignerey, E.-J. Kim, R. A. Soltz, S. Gushue, J. Luke, K. Yagi, M. N. Namboodiri, W. Eldredge, C. Chasman, Jongmin Lee, J. Engelage, Ryugo S. Hayano, S. Nagamiya, Kenta Shigaki, C. Y. Chi, K. Ashktorab, Y. D. Wu, E. Garcia, D. R. Beavis, A. Kumagai, F. Zhu, K. Kurita, S. Ueno-Hayashi, H. B. Yao, L. P. Remsberg, Y. Y. Chu, W. A. Zajc, Y. Akiba, J. H. Kang, M. J. Tannenbaum, R. Seto, B. Moskowitz, M. D. Baker, H. J. Crawford, Brian Cole, C. A. Ogilvie, M. Moulson, Yasuo Miake, S. Y. Fung, Z. Chen, J. H. Thomas, V. Cianciolo, Fuqiang Wang, T. C. Sangster, J. Shea, G. Heintzelman, H. C. Britt, H. Xiang, E. G. Judd, H. Sako, J. C. Dunlop, George Stephans, F. Videbæk, J. Chang, R. R. Debbe, S. G. Steadman, G. H. Xu, Luisa F. Hansen, L. Ahle, J. B. Cumming, C. Muentz, and Hideki Hamagaki

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Particle physics, Pion, Proton, Physics beyond the Standard Model, Observable, Multiplicity (chemistry), Nuclear Experiment, Event (particle physics), Energy (signal processing), Spectral line
Abstract

In this paper Au+Au collisions at 11.6A GeV/c are characterized by two global observables: the energy measured near zero degrees (E{sub ZCAL}) and the total event multiplicity. Particle spectra are measured for different event classes that are defined in a two-dimensional grid of both global observables. For moderately central events ({sigma}/{sigma}{sub int}{lt}12{percent}) the proton dN/dy distributions do not depend on E{sub ZCAL} but only on the event multiplicity. In contrast the shape of the proton transverse spectra shows little dependence on the event multiplicity. The change in the proton dN/dy distributions suggests that different conditions are formed in the collision for different event classes. These event classes are studied for signals of new physics by measuring pion and kaon spectra and yields. In the event classes doubly selected on E{sub ZCAL} and multiplicity there is no indication of any unusual pion or kaon yields, spectra, or K/{pi} ratio even in the events with extreme multiplicity. {copyright} {ital 1999} {ital The American Physical Society}

Published
1999
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5. Kaon production in Au+Au collisions at11.6A GeV/c

Author

J. Luke, Alice Mignerey, L. P. Remsberg, J. H. Kang, F. Zhu, M. D. Baker, H. C. Britt, R. R. Debbe, Y. Y. Chu, B. Cole, S. G. Steadman, C. A. Ogilvie, G. H. Xu, G. Heintzelman, F. Videbæk, J. Chang, K. Kurita, Yasuo Miake, J.W. Olness, J. Engelage, H. Hamagaki, R. Seto, M. J. Tannenbaum, Z. Chen, L. Ahle, B. Moskowitz, S. Ueno-Hayashi, V. Cianciolo, K. Yagi, M. N. Namboodiri, Ryugo S. Hayano, Fuqiang Wang, H. J. Crawford, Kenta Shigaki, C. Y. Chi, Luisa F. Hansen, J. H. Thomas, D. R. Beavis, C. Chasman, T. C. Sangster, Y. Akiba, Jongmin Lee, E. G. Judd, R. A. Soltz, S. Gushue, A. Kumagai, E.-J. Kim, H. Xiang, K. Ashktorab, C. Muentz, J. B. Cumming, J. Shea, H. Sako, H. B. Yao, J. C. Dunlop, E. Garcia, George Stephans, S. Nagamiya, Y. D. Wu, S. Y. Fung, W. A. Zajc, W. Eldredge, and M. Moulson

Subjects
Physics, Nuclear physics, Nuclear reaction, Nuclear and High Energy Physics, Nuclear Theory, Quark model, Hadron, Inverse, Production (computer science), Rapidity, Nuclear Experiment, Energy (signal processing), Spectral line
Abstract

A systematic study of the spectra and yields of K{sup +} and K{sup {minus}} is reported by experiment E866 as a function of centrality in Au+Au collisions at 11.6A GeV/c. The invariant transverse spectra for both kaon species are well described by exponentials in m{sub t}, with inverse slope parameters that are largest at midrapidity and which increase with centrality. The inverse slopes of the K{sup +} spectra are slightly larger than the inverse slopes of the K{sup {minus}} spectra. The kaon rapidity density peaks at midrapidity with the K{sup +} distribution wider in rapidity than K{sup {minus}}. The integrated total yields of K{sup +} and K{sup {minus}} increase nonlinearly and steadily with the number of projectile participants. The yield per participant for kaons is two to three times larger than the yield from N-N collisions. This enhancement suggests that the majority of kaons in central Au+Au reactions are produced in secondary hadronic collisions. There is no evidence for an onset of additional kaon production from a possible small volume of baryon-rich quark-gluon plasma. The differences between K{sup +} and K{sup {minus}} rapidity distributions and transverse spectra are consistent with a lower phase space for K{sup {minus}} production due tomore » a higher energy threshold. These differences also exclude simple thermal models that assume emission from a common equilibrated system. {copyright} {ital 1998} {ital The American Physical Society}« less

Published
1998
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6. Antiproton Production inAu+AuCollisions at11.7AGeV/c

Author

Ryugo S. Hayano, J. Chang, Kenta Shigaki, F. Zhu, S. Y. Fung, J. C. Dunlop, H. Sako, J. B. Cumming, L. P. Remsberg, J. H. Kang, S. Nagamiya, Yang Wu, R. A. Soltz, Brian Cole, S. Gushue, K. Kurita, D. R. Beavis, J. Luke, H. Xiang, J.W. Olness, C. Chasman, K. Ashktorab, W. A. Zajc, L. Ahle, J. H. Thomas, Jongmin Lee, T. C. Sangster, E. Garcia, R. Seto, V. Cianciolo, M. D. Baker, S. Ueno-Hayashi, F. Videbæk, C. Muentz, R. R. Debbe, J. Engelage, Y. Y. Chu, J. Shea, S. G. Steadman, C. A. Ogilvie, C. Y. Chi, M. Moulson, G. H. Xu, George Stephans, Yasuo Miake, Fuqiang Wang, E. G. Judd, E. J. Kim, Hideki Hamagaki, Luisa F. Hansen, G. Heintzelman, Z. Chen, H. Yao, W. Eldredge, A. Kumagai, M. J. Tannenbaum, H. J. Crawford, Alice Mignerey, H. C. Britt, Y. Akiba, B. Moskowitz, K. Yagi, and M. N. Namboodiri

Subjects
Physics, Nuclear Theory, Nuclear structure, General Physics and Astronomy, Kinetic energy, Nuclear matter, Nuclear physics, Antiproton, Antimatter, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, Nucleon, Scaling
Abstract

Antiproton production in 11.7A GeV/c Au+Au collisions over a wide transverse-mass coverage was studied using the AGS-E866 experimental apparatus. The mean transverse kinetic energy increases as a function of centrality and is similar to that of protons. The antiproton yields in Si+Al , Si+Au , and Au+Au collisions are consistent with scaling with the 0.7 power of the number of participant nucleons. Copyright 1998, The American Physical Society

Published
1998
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7. An excitation function at the AGS: E917 — Probing the dynamics of heavy ion collisions

Author

Russell Richard Betts, W. Eldredge, J. Chang, Ju Hwan Kang, A. H. Wuosmaa, H. B. Yao, Youngil Kwon, J. B. Cumming, P. J. Stanskas, A. Ruangma, J. C. Dunlop, C. M. Zou, S. Y. Kim, B. B. Back, F.L.H. Wolfs, M. Moulson, H. C. Britt, V. Nanal, C. Y. Chi, R. Seto, E.-J. Kim, R. Pak, W. C. Chang, D. Russ, S. Y. Fung, H. Wang, D. J. Hofman, D. McLeod, C. A. Ogilvie, Y. Y. Chu, Burt Holzman, H. Xiang, G. Heintzelman, W. Henning, George Stephans, A. Gillitzer, E. J. Garcia-Solis, R. Ganz, G. H. Xu, and Alice Mignerey

Subjects
Physics, Excitation function, Nuclear and High Energy Physics, SIMPLE (dark matter experiment), Pion, Nuclear Theory, Dynamics (mechanics), Particle, Heavy ion, Atomic physics, Nuclear Experiment, Beam energy, Spectral line
Abstract

Particle yields and spectra for kaons, pions and protons have been measured as a function of beam energy in Au Au collisions at the AGS. The energy dependence of the yields indicates that increased beam energy leads primarily to an increase in particle production with a slight increase in transverse momentum. The measured 〈 m T 〉 distributions have been fit to a simple model which assumes a thermal distribution with an additional term proportional to the particle mass. This additional term can be attributed to collective expansion.

Published
1998
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8. Proton, deuteron, and triton emission at target rapidity in Au+Au collisions at10.20AGeV: Spectra and directed flow

Author

K. Ashktorab, Fuqiang Wang, S. Homma, S. Ueno-Hayashi, B. Moskowitz, M. Moulson, R. A. Soltz, H. Sako, Y. D. Wu, T. C. Sangster, K. Kurita, S. Gushue, R. Seto, T. Sung, J. Luke, W. A. Zajc, Daniel S. Zachary, Hideki Hamagaki, D. R. Beavis, V. Cianciolo, M. Gonin, Q. Zhu, M. J. LeVine, M. J. Tannenbaum, Ryugo S. Hayano, L. Hansen, F. Zhu, E. G. Judd, Y. Y. Chu, C. Chasman, H. J. Crawford, J. Engelage, F. Videbæk, J. Chang, Kenta Shigaki, C. Y. Chi, L. P. Remsberg, S. Y. Fung, J. H. Kang, J. B. Cumming, S. Nagamiya, J. J. Gaardhoje, M. D. Baker, Z. Chen, Brian Cole, A. Kumagai, W. Eldredge, T. K. Nayak, J. H. Thomas, G. Heintzelman, H. C. Britt, J.W. Olness, D. S. Woodruff, C. A. Ogilvie, George Stephans, Yasuo Miake, Y. Wang, Y. Akiba, S. Tonse, K. Yagi, M. N. Namboodiri, L. Ahle, Alex Hansen, H. Kaneko, R. R. Debbe, S. G. Steadman, and G. H. Xu

Subjects
Physics, Nuclear and High Energy Physics, Proton, Nuclear Theory, Spectral line, Nuclear physics, Hodoscope, Deuterium, Pseudorapidity, Rapidity, Emission spectrum, Atomic physics, Nuclear Experiment, Energy (signal processing)
Abstract

Systematic results are presented on proton, deuteron, and triton emission from the target spectator region in collisions of 10.20A GeV gold projectiles with a gold target. A forward hodoscope utilizes detection of projectile spectator fragments to determine the orientation of the reaction plane, event by event. The directed flow {l_angle}p{sub x}{r_angle} is determined as a function of pseudorapidity. Projectile spectator energy is used to estimate impact parameters. Results are compared to current theoretical models ARC, ART, and RQMD. In all cases good agreement with theory is obtained for calculations utilizing a pure cascade without nuclear potential contributions. {copyright} {ital 1998} {ital The American Physical Society}

Published
1998
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9. Particle production at high baryon density in central Au+Au reactions at 11.6AGeV/c

Author

T. Sung, Alice Mignerey, S. Tonse, L. Hansen, J. Shea, K. Yagi, M. N. Namboodiri, C. Muentz, C. A. Ogilvie, E. G. Judd, Yasuo Miake, R. R. Debbe, Y. Wang, F. Videbæk, J. Chang, S. G. Steadman, H. Xiang, G. H. Xu, P. Rothschild, J. Luke, M. J. Tannenbaum, S. Nagamiya, K. Ashktorab, Daniel S. Zachary, J. J. Gaardhøje, Hideki Hamagaki, H. J. Crawford, G. Heintzelman, M. Gonin, W. Eldredge, Brian Cole, J. H. Thomas, Q. Zhu, L. Ahle, D. R. Beavis, Alex Hansen, Y. Akiba, M. J. LeVine, J. B. Cumming, E.-J. Kim, H. Kaneko, C. Chasman, H. C. Britt, S. Ueno-Hayashi, B. Moskowitz, Y. Y. Chu, A. Kumagai, Jongmin Lee, E. Garcia, S. Park, Z. Chen, R. A. Soltz, S. Gushue, V. Cianciolo, Fuqiang Wang, T. C. Sangster, K. Kurita, J. Engelage, Ryugo S. Hayano, Kenta Shigaki, C. Y. Chi, L. P. Remsberg, J. H. Kang, M. D. Baker, M. Moulson, F. Zhu, George Stephans, D. P. Morrison, H. Sako, J. C. Dunlop, R. Seto, J.W. Olness, S. Y. Fung, W. A. Zajc, S. Homma, and Y. D. Wu

Subjects
Physics, Nuclear and High Energy Physics, Proton, Nuclear Theory, Nuclear matter, Spectral line, Ion, Nuclear physics, Baryon, Pion, State of matter, Rapidity, Atomic physics, Nuclear Experiment
Abstract

Semi-inclusive proton and pion distributions from central Au+Au reactions at 11.6A GeV/c have been measured. The proton rapidity distribution shows significantly increased stopping compared to lighter systems, providing strong evidence for the formation of a state of matter with baryon density substantially greater than normal nuclear matter. Unlike reactions at this energy induced by lighter heavy ions, at low m{sub t}-m{sub 0} the proton invariant spectra deviate from a single exponential shape and become flatter, while {pi}{sup {minus}} spectra are found to rise faster than the {pi}{sup +} spectra. {copyright} {ital 1998} {ital The American Physical Society}

Published
1998
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10. Recent results from E866

Author

W. Eldredge, M. Moulson, L. Ahle, Alice Mignerey, J.W. Olness, J. Luke, L. P. Remsberg, Hideki Hamagaki, Y. Wang, George Stephans, H. C. Britt, H. Kaneko, M. Gonin, H. Sako, Q. Zhu, M. Le Vine, J. H. Kang, Brian Cole, C. Chasman, J. H. Thomas, E.-J. Kim, R. R. Debbe, D. S. Woodruff, S. Gushue, S. G. Steadman, J. Ryan, W. A. Zajc, M. D. Baker, G. H. Xu, J. Engelage, Jongmin Lee, J. B. Cumming, S. Nagamiya, M. J. Tannenbaum, S. Hayashi, B. Moskowitz, H. J. Crawford, Z. Chen, D. R. Beavis, S. Y. Fung, H. Xiang, F. Zhu, V. Cianciolo, H. Liu, K. Ashktorab, R. Seto, Fuqiang Wang, Y. Y. Chu, T. C. Sangster, F. Videbæk, J. Chang, X. Yang, S. Homma, Y. D. Wu, Luisa F. Hansen, G. Heintzelman, E. G. Judd, Ryugo S. Hayano, Kenta Shigaki, C. Y. Chi, K. Kurita, J. Shea, C. A. Ogilvie, Yasuo Miake, R. A. Soltz, Y. Akiba, A. Kumagai, K. Yagi, and M. N. Namboodiri

Subjects
Quark, Physics, Nuclear and High Energy Physics, Particle physics, Meson, Spectrometer, Nuclear Theory, Multiplicity (mathematics), Nuclear physics, Strange matter, Pion, Reaction dynamics, High Energy Physics::Experiment, Rapidity, Nuclear Experiment
Abstract

The E866 experimental setup has been upgraded by addition of a forward spectrometer to handle the large multiplicities in central Au+Au collisions at AGS. Furthermore new global detectors have been added to gain insight into the reaction dynamics and enable studies of flow effects. The report presents preliminary rapidity distributions for protons and produced mesons in central collisions. The shape of m{sub t}-spectra of pions is discussed. Examples of the measurements which can be done with a new multiplicity array are presented.

Published
1995
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11. System, centrality, and transverse mass dependence of two-pion correlation radii in heavy ion collisions at11.6Aand14.6AGeV/c

Author

B. Budick, H. Kaneko, W. L. Kehoe, R. A. Soltz, S. Gushue, A. Kumagai, C. G. Parsons, J. Engelage, Brian Cole, S. B. Kaufman, J. H. Thomas, R. J. Morse, J. Shea, Ryugo S. Hayano, Kenta Shigaki, J. Luke, C. Müntz, L. Ahle, C. Y. Chi, K. Ashktorab, S. Y. Fung, Y. Tanaka, V. Cianciolo, J.W. Olness, Jongmin Lee, H. B. Yao, O. Vossnack, Y. Y. Chu, George Stephans, R. R. Debbe, T. C. Sangster, M. D. Baker, S. G. Steadman, W. Eldredge, G. H. Xu, Y. D. Wu, D. P. Morrison, Z. Chen, D. R. Beavis, J. H. van Dijk, J. B. Cumming, W. A. Zajc, P. Stankus, H. C. Britt, K. Kurita, S. Hayashi, B. Moskowitz, V. Vutsadakis, S. Homma, Y. Wang, M. Moulson, J. B. Costales, E. Judd, H. Sako, P. Beery, X. Yang, E.-J. Kim, F. Wang, Daniel S. Zachary, Hideki Hamagaki, P. Rothschild, D. S. Woodruff, E. Garcia, R. Seto, J. C. Dunlop, M. Gonin, M. J. LeVine, C. Chasman, M. J. Tannenbaum, J. Kang, H. J. Crawford, Alice Mignerey, S. Ueno-Hayashi, S. Nagamiya, T. K. Nayak, L. P. Remsberg, S. Tonse, K. Yagi, M. N. Namboodiri, H. E. Wegner, Y. Akiba, F. Videbæk, J. Chang, G. Heintzelman, F. Zhu, Luisa F. Hansen, Hiroyoshi Sakurai, T. Sung, H. Xiang, D. Roehrich, R. J. Ledoux, C. A. Ogilvie, and Yasuo Miake

Subjects
Physics, Nuclear and High Energy Physics, Range (particle radiation), Projectile, Nuclear Theory, Radius, Nuclear physics, Pion, Transverse mass, Atomic physics, Nuclear Experiment, Parametrization, Glauber, Reference frame
Abstract

Two-pion correlation functions are analyzed at mid-rapidity for three systems (14.6 A-GeV Si+Al, Si+Au, and 11.6 A-GeV Au+Au), seven distinct centrality conditions, and different kT bins in the range 0.1--0.5 GeV/c. Source reference frames are determined from fits to the Yano-Koonin source parameterization. Bertsch-Pratt radius parameters are shown to scale linearly with both number of projectile and total participants as obtained from a Glauber model calculation. A finite emission duration that increases linearly with system/centrality is also reported. The mT dependence of the Bertsch-Pratt radii is measured for the central Si+Au and Au+Au systems. The system/centrality dependence is investigated separately for both high and low mT regions.

Published
2002
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12. Baryon Rapidity Loss in Relativistic Au+Au Collisions

Author

Alice Mignerey, Eun Jin Kim, Y. Y. Chu, R. Pak, W. C. Chang, W. Eldredge, H. B. Yao, E. Garcia, V. Nanal, C. Y. Chi, C. M. Zou, S. Y. Kim, J. B. Cumming, R. Seto, F. E.H. Wolfs, H. Xiang, George Stephans, S. Y. Fung, J. Chang, A. H. Wuosmaa, P. J. Stanskas, A. Ruangma, H. Wang, G. Heintzelman, Ju Hwan Kang, B. B. Back, G. H. Xu, M. Moulson, C. A. Ogilvie, David Jonathan Hofman, D. E. Russ, R. Ganz, Russell Richard Betts, D. McLeod, Y. J. Kwon, J. C. Dunlop, Burt Holzman, A. Gillitzer, and W. F. Henning

Subjects
Excitation function, Physics, Proton, 010308 nuclear & particles physics, Isotropy, Nuclear Theory, General Physics and Astronomy, FOS: Physical sciences, 01 natural sciences, Nuclear physics, Baryon, 0103 physical sciences, Rapidity, Atomic physics, Nuclear Experiment (nucl-ex), 010306 general physics, Nucleon, Nuclear Experiment, Beam energy
Abstract

An excitation function of proton rapidity distributions for different centralities is reported from AGS Experiment E917 for Au+Au collisions at 6, 8, and 10.8 GeV/nucleon. The rapidity distributions from peripheral collisions have a valley at midrapidity which smoothly change to distributions that peak at midrapidity for central collisions. The mean rapidity loss increases with increasing beam energy, whereas the fraction of protons consistent with isotropic emission from a thermal source at midrapidity decreases with increasing beam energy., Comment: 9 pages, 3 figures, 1 table replaced version has figures rotated

Published
2000
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13. Proton and deuteron production in Au+Au reactions at11.6A GeV/c

Author

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
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14. Centrality dependence of kaon yields inSi+Aand Au+Au collisions at relativistic energies

Author

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
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15. E917 at the AGS: High Density Baryon Matter

Author

Eun Jin Kim, R. R. Betts, F. L. H. Wolfs, R. Ganz, M. Moulson, Ju Hwan Kang, D. E. Russ, H. B. Yao, G. Heintzelman, Sewha Kim, Y. Y. Chu, George Stephans, Y. J. Kwon, E. J. Garcia-Solis, J. Chang, Burt Holzman, V. Nanal, J. C. Dunlop, W. Eldredge, C. M. Zou, A. H. Wuosmaa, W. F. Henning, D. McLeod, C. Y. Chi, Alice Mignerey, R. Seto, D. J. Hofman, H. Wang, W. C. Chang, A. Gillitzer, P. J. Stanskas, B. B. Back, S. Y. Fung, G. H. Xu, A. Ruangma, H. C. Britt, J. B. Cumming, H. Xiang, R. Pak, and C. A. Ogilvie

Subjects
Physics, Excitation function, Particle physics, High Energy Physics::Phenomenology, Nuclear Theory, Hadron, High density, Plasma, Alternating Gradient Synchrotron, Nuclear matter, Signal, Baryon, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Nuclear matter of high density is created during the collisions of Au+Au nuclei using the Alternating Gradient Synchrotron (AGS) located at Brookhaven National Laboratory.1, 2 Whether the formation of a quark-gluon plasma (QGP) occurs during these heavy-ion collisions, or even if it is possible to extract an unambiguous signal of its existence from the background of hadronic debris, remains highly speculative. Regardless of whether a QGP is created, the potential exists to do a great deal of interesting and exciting physics with the high density baryonic matter created during the Au+Au collisions at the AGS.

Published
1998
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