Systematic measurements of identified particle spectra in pp, d plus Au, and Au plus Au collisions at the STAR detector

doi:10.1103/PhysRevC.79.034909

	Systematic measurements of identified particle spectra in pp, d plus Au, and Au plus Au collisions at the STAR detector
	Abelev, B. I.2; Aggarwal, M. M.25; Ahammed, Z.11; Anderson, B. D.37; Arkhipkin, D.43; Averichev, G. S.4; Bai, Y.27,28; Balewski, J.; Barannikova, O.2; Barnby, L. S.52
刊名	PHYSICAL REVIEW C
	2009-03-01
卷号	79 页码:58
ISSN号	0556-2813
DOI	10.1103/PhysRevC.79.034909
英文摘要	Identified charged-particle spectra of pi(+/-), K-+/-, p, and (p) over bar at midrapidity (vertical bar y vertical bar < 0.1) measured by the dE/dx method in the STAR (solenoidal tracker at the BNL Relativistic Heavy Ion Collider) time projection chamber are reported for pp and d + Au collisions at root s(NN) = 200 GeV and for Au + Au collisions at 62.4, 130, and 200 GeV. Average transverse momenta, total particle production, particle yield ratios, strangeness, and baryon production rates are investigated as a function of the collision system and centrality. The transverse momentum spectra are found to be flatter for heavy particles than for light particles in all collision systems; the effect is more prominent for more central collisions. The extracted average transverse momentum of each particle species follows a trend determined by the total charged-particle multiplicity density. The Bjorken energy density estimate is at least several GeV/fm(3) for a formation time less than 1 fm/c. A significantly larger net-baryon density and a stronger increase of the net-baryon density with centrality are found in Au + Au collisions at 62.4 GeV than at the two higher energies. Antibaryon production relative to total particle multiplicity is found to be constant over centrality, but increases with the collision energy. Strangeness production relative to total particle multiplicity is similar at the three measured RHIC energies. Relative strangeness production increases quickly with centrality in peripheral Au + Au collisions, to a value about 50% above the pp value, and remains rather constant in more central collisions. Bulk freeze-out properties are extracted from thermal equilibrium model and hydrodynamics-motivated blast-wave model fits to the data. Resonance decays are found to have little effect on the extracted kinetic freeze-out parameters because of the transverse momentum range of our measurements. The extracted chemical freeze-out temperature is constant, independent of collision system or centrality; its value is close to the predicted phase-transition temperature, suggesting that chemical freeze-out happens in the vicinity of hadronization and the chemical freeze-out temperature is universal despite the vastly different initial conditions in the collision systems. The extracted kinetic freeze-out temperature, while similar to the chemical freeze-out temperature in pp, d + Au, and peripheral Au + Au collisions, drops significantly with centrality in Au + Au collisions, whereas the extracted transverse radial flow velocity increases rapidly with centrality. There appears to be a prolonged period of particle elastic scatterings from chemical to kinetic freeze-out in central Au + Au collisions. The bulk properties extracted at chemical and kinetic freeze-out are observed to evolve smoothly over the measured energy range, collision systems, and collision centralities.
资助项目	Science and Technology Facilities Council[PP/F001061/1]
WOS关键词	HEAVY-ION COLLISIONS ; QUARK-GLUON-PLASMA ; NUCLEUS-NUCLEUS COLLISIONS ; TIME PROJECTION CHAMBER ; IMPACT PARAMETER REPRESENTATION ; PROTON-ANTIPROTON COLLISIONS ; TRANSVERSE-MOMENTUM SPECTRA ; RESISTIVE PLATE CHAMBERS ; HIGH-DENSITY QCD ; AU+AU COLLISIONS
WOS研究方向	Physics
语种	英语
出版者	AMER PHYSICAL SOC
WOS记录号	WOS:000264766100047
内容类型	期刊论文
源URL	[http://119.78.100.186/handle/113462/30466]
专题	中国科学院近代物理研究所
通讯作者	Abelev, B. I.
作者单位	1.Penn State Univ, University Pk, PA 16802 USA 2.Univ Illinois, Chicago, IL 60607 USA 3.USN Acad, Annapolis, MD 21402 USA 4.Joint Inst Nucl Res Dubna, Lab High Energy, Dubna, Russia 5.Univ Zagreb, HR-10002 Zagreb, Croatia 6.Yale Univ, New Haven, CT 06520 USA 7.CCNU HZNU, Inst Particle Phys, Wuhan 430079, Peoples R China 8.Wayne State Univ, Detroit, MI 48201 USA 9.Univ Washington, Seattle, WA 98195 USA 10.Warsaw Univ Technol, Warsaw, Poland
推荐引用方式 GB/T 7714	Abelev, B. I.,Aggarwal, M. M.,Ahammed, Z.,et al. Systematic measurements of identified particle spectra in pp, d plus Au, and Au plus Au collisions at the STAR detector[J]. PHYSICAL REVIEW C,2009,79:58.
APA	Abelev, B. I..,Aggarwal, M. M..,Ahammed, Z..,Anderson, B. D..,Arkhipkin, D..,...&Zuo, J. X..(2009).Systematic measurements of identified particle spectra in pp, d plus Au, and Au plus Au collisions at the STAR detector.PHYSICAL REVIEW C,79,58.
MLA	Abelev, B. I.,et al."Systematic measurements of identified particle spectra in pp, d plus Au, and Au plus Au collisions at the STAR detector".PHYSICAL REVIEW C 79(2009):58.