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Title: Production of strange particles at intermediate p{sub T} in central Au+Au collisions at high energies

Abstract

The recombination model is applied to the production of K,{phi},{lambda} , and {omega} at all p{sub T} in central Au+Au collisions. The thermal-shower component of the recombination is found to be important for K and {lambda}, but only in a minor way for {phi} and {omega} in the intermediate to high p{sub T} region. The normalization and inverse slope of the thermal partons in the strange sector are determined by fitting the low-p{sub T} data. At higher p{sub T} the data of K,{lambda},{phi}, and {omega} in the log scale are all well reproduced in our study that extends the thermal contribution and includes the shower contribution. The calculated result on the {lambda}/K ratio rises to a maximum of around 2 at p{sub T}{approx_equal}4 GeV/c, arching over the data in linear scale. The production of {phi} and {omega} are shown to arise mainly from the recombination of thermal partons, thus exhibiting exponential p{sub T} dependences in agreement with the data. Their ratio, R{sub {omega}}{sub /{phi}}, rises linearly to p{sub T}{approx_equal}4 GeV/c and develops a maximum at p{sub T}{approx_equal}5.5 GeV/c. It is argued that the p{sub T} spectra of {phi} and {omega} reveal directly the partonic nature of the thermal source thatmore » characterizes quark-gluon plasma. Comments are made on the {omega} puzzle due to the simultaneous observation of both the exponential behavior of the {omega} spectrum in p{sub T} and the existence of low-p{sub T} particles associated with {omega} as trigger.« less

Authors:
 [1];  [1];  [2]
  1. Institute of Theoretical Science and Department of Physics, University of Oregon, Eugene, Oregon 97403-5203 (United States)
  2. (China)
Publication Date:
OSTI Identifier:
20995308
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevC.75.054904; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; COLLISIONS; GEV RANGE 01-10; GOLD 197 REACTIONS; GOLD 197 TARGET; MASS NUMBER; OMEGA BARYONS; PARTICLE PRODUCTION; QUARK MATTER; RECOMBINATION; SPECTRA

Citation Formats

Hwa, Rudolph C., Yang, C. B., and Institute of Particle Physics, Hua-Zhong Normal University, Wuhan 430079. Production of strange particles at intermediate p{sub T} in central Au+Au collisions at high energies. United States: N. p., 2007. Web. doi:10.1103/PHYSREVC.75.054904.
Hwa, Rudolph C., Yang, C. B., & Institute of Particle Physics, Hua-Zhong Normal University, Wuhan 430079. Production of strange particles at intermediate p{sub T} in central Au+Au collisions at high energies. United States. doi:10.1103/PHYSREVC.75.054904.
Hwa, Rudolph C., Yang, C. B., and Institute of Particle Physics, Hua-Zhong Normal University, Wuhan 430079. Tue . "Production of strange particles at intermediate p{sub T} in central Au+Au collisions at high energies". United States. doi:10.1103/PHYSREVC.75.054904.
@article{osti_20995308,
title = {Production of strange particles at intermediate p{sub T} in central Au+Au collisions at high energies},
author = {Hwa, Rudolph C. and Yang, C. B. and Institute of Particle Physics, Hua-Zhong Normal University, Wuhan 430079},
abstractNote = {The recombination model is applied to the production of K,{phi},{lambda} , and {omega} at all p{sub T} in central Au+Au collisions. The thermal-shower component of the recombination is found to be important for K and {lambda}, but only in a minor way for {phi} and {omega} in the intermediate to high p{sub T} region. The normalization and inverse slope of the thermal partons in the strange sector are determined by fitting the low-p{sub T} data. At higher p{sub T} the data of K,{lambda},{phi}, and {omega} in the log scale are all well reproduced in our study that extends the thermal contribution and includes the shower contribution. The calculated result on the {lambda}/K ratio rises to a maximum of around 2 at p{sub T}{approx_equal}4 GeV/c, arching over the data in linear scale. The production of {phi} and {omega} are shown to arise mainly from the recombination of thermal partons, thus exhibiting exponential p{sub T} dependences in agreement with the data. Their ratio, R{sub {omega}}{sub /{phi}}, rises linearly to p{sub T}{approx_equal}4 GeV/c and develops a maximum at p{sub T}{approx_equal}5.5 GeV/c. It is argued that the p{sub T} spectra of {phi} and {omega} reveal directly the partonic nature of the thermal source that characterizes quark-gluon plasma. Comments are made on the {omega} puzzle due to the simultaneous observation of both the exponential behavior of the {omega} spectrum in p{sub T} and the existence of low-p{sub T} particles associated with {omega} as trigger.},
doi = {10.1103/PHYSREVC.75.054904},
journal = {Physical Review. C, Nuclear Physics},
number = 5,
volume = 75,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
  • We present STAR measurements of charged hadron production as a function of centrality in Au + Au collisions at {radical}s{sub NN} = 130 GeV. The measurements cover a phase space region of 0.2 < p{sub T} < 6.0 GeV/c in transverse momentum and 11 < {eta} < 1 in pseudorapidity. Inclusive transverse momentum distributions of charged hadrons in the pseudorapidity region 0.5 < |{eta}| < 1 are reported and compared to our previously published results for |{eta}| < 0.5. No significant difference is seen for inclusive p{sub T} distributions of charged hadrons in these two pseudorapidity bins. We measured dN/d{eta}more » distributions and truncated mean p{sub T} in a region of p{sub T} > P{sub T}{sup cut}, and studied the results in the framework of participant and binary scaling. No clear evidence is observed for participant scaling of charged hadron yield in the measured pT region. The relative importance of hard scattering process is investigated through binary scaling fraction of particle production.« less
  • We present STAR measurements of charged hadron production as a function of centrality in Au + Au collisions at {radical}s{sub NN} = 130 GeV. The measurements cover a phase space region of 0.2 < p{sub T} < 6.0 GeV/c in transverse momentum and -1 < {eta} < 1 in pseudorapidity. Inclusive transverse momentum distributions of charged hadrons in the pseudorapidity region 0.5 < |{eta}| < 1 are reported and compared to our previously published results for |{eta}| < 0.5. No significant difference is seen for inclusive p{sub T} distributions of charged hadrons in these two pseudorapidity bins. We measured dN/d{eta}more » distributions and truncated mean p{sub T} in a region of p{sub T} > p{sub T}{sup cut}, and studied the results in the framework of participant and binary scaling. No clear evidence is observed for participant scaling of charged hadron yield in the measured p{sub T} region. The relative importance of hard scattering process is investigated through binary scaling fraction of particle production.« less
  • We present STAR measurements of charged hadron production as a function of centrality in Au+Au collisions at {radical}(s{sub NN})=130 GeV. The measurements cover a phase space region of 0.2<p{sub T}<6.0 GeV/c in transverse momentum and -1<{eta}<1 in pseudorapidity. Inclusive transverse momentum distributions of charged hadrons in the pseudorapidity region 0.5< vertical bar {eta} vertical bar <1 are reported and compared to our previously published results for vertical bar {eta} vertical bar <0.5. No significant difference is seen for inclusive p{sub T} distributions of charged hadrons in these two pseudorapidity bins. We measured dN/d{eta} distributions and truncated mean p{sub T} inmore » a region of p{sub T}>p{sub T}{sup cut}, and studied the results in the framework of participant and binary scaling. No clear evidence is observed for participant scaling of charged hadron yield in the measured p{sub T} region. The relative importance of hard scattering processes is investigated through binary scaling fraction of particle production.« less
  • Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudo-rapidity range and full azimuth in Au+Au and p+p collisions at = {radical}s{sub NN} = 200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes already observed in elementary collisions. A strong back-to-back correlation exists for p+p and peripheral Au + Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.
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