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Title: Scaling properties of hyperon production in Au+Au collisons at {radical}{ovr s} {sub NN} = 200 GeV.

Abstract

We present the scaling properties of {Lambda}, {Xi}, and {Omega} in midrapidity Au+Au collisions at the Brookhaven National Laboratory Relativistic Heavy Ion Collider at {radical}s{sub NN} = 200 GeV. The yield of multistrange baryons per participant nucleon increases from peripheral to central collisions more rapidly than that of {Lambda}, indicating an increase of the strange-quark density of the matter produced. The strange phase-space occupancy factor {gamma}{sub s} approaches unity for the most central collisions. Moreover, the nuclear modification factors of p, {Lambda}, and {Xi} are consistent with each other for 2 < p{sub T} < 5 GeV/c in agreement with a scenario of hadron formation from constituent quark degrees of freedom.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC); National Science Foundation (NSF)
OSTI Identifier:
965754
Report Number(s):
ANL-HEP-PR-09-59
Journal ID: ISSN 0031-9007; PRLTAO; TRN: US0903695
DOE Contract Number:
DE-AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Phys. Rev. Lett.; Journal Volume: 98; Journal Issue: 2007
Country of Publication:
United States
Language:
ENGLISH
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 74 ATOMIC AND MOLECULAR PHYSICS; BARYONS; BNL; DEGREES OF FREEDOM; HADRONS; HEAVY IONS; HYPERONS; MODIFICATIONS; NUCLEONS; PHASE SPACE; PRODUCTION; QUARKS

Citation Formats

Cadman, R. V., Krueger, K., Spinka, H. M., McClain, C. J., Underwood, D. G., Adams, J., Aggarwal, M. M., Ahammed, Z., Amonett, J., Anderson, M., STAR Collaboration, High Energy Physics, Univ. of Birmingham, Panjab Univ., Variable Energy Cyclotron Centre, and Kent State Univ. Scaling properties of hyperon production in Au+Au collisons at {radical}{ovr s} {sub NN} = 200 GeV.. United States: N. p., 2007. Web. doi:10.1103/PhysRevLett.98.062301.
Cadman, R. V., Krueger, K., Spinka, H. M., McClain, C. J., Underwood, D. G., Adams, J., Aggarwal, M. M., Ahammed, Z., Amonett, J., Anderson, M., STAR Collaboration, High Energy Physics, Univ. of Birmingham, Panjab Univ., Variable Energy Cyclotron Centre, & Kent State Univ. Scaling properties of hyperon production in Au+Au collisons at {radical}{ovr s} {sub NN} = 200 GeV.. United States. doi:10.1103/PhysRevLett.98.062301.
Cadman, R. V., Krueger, K., Spinka, H. M., McClain, C. J., Underwood, D. G., Adams, J., Aggarwal, M. M., Ahammed, Z., Amonett, J., Anderson, M., STAR Collaboration, High Energy Physics, Univ. of Birmingham, Panjab Univ., Variable Energy Cyclotron Centre, and Kent State Univ. Mon . "Scaling properties of hyperon production in Au+Au collisons at {radical}{ovr s} {sub NN} = 200 GeV.". United States. doi:10.1103/PhysRevLett.98.062301.
@article{osti_965754,
title = {Scaling properties of hyperon production in Au+Au collisons at {radical}{ovr s} {sub NN} = 200 GeV.},
author = {Cadman, R. V. and Krueger, K. and Spinka, H. M. and McClain, C. J. and Underwood, D. G. and Adams, J. and Aggarwal, M. M. and Ahammed, Z. and Amonett, J. and Anderson, M. and STAR Collaboration and High Energy Physics and Univ. of Birmingham and Panjab Univ. and Variable Energy Cyclotron Centre and Kent State Univ.},
abstractNote = {We present the scaling properties of {Lambda}, {Xi}, and {Omega} in midrapidity Au+Au collisions at the Brookhaven National Laboratory Relativistic Heavy Ion Collider at {radical}s{sub NN} = 200 GeV. The yield of multistrange baryons per participant nucleon increases from peripheral to central collisions more rapidly than that of {Lambda}, indicating an increase of the strange-quark density of the matter produced. The strange phase-space occupancy factor {gamma}{sub s} approaches unity for the most central collisions. Moreover, the nuclear modification factors of p, {Lambda}, and {Xi} are consistent with each other for 2 < p{sub T} < 5 GeV/c in agreement with a scenario of hadron formation from constituent quark degrees of freedom.},
doi = {10.1103/PhysRevLett.98.062301},
journal = {Phys. Rev. Lett.},
number = 2007,
volume = 98,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • We present the scaling properties of {lambda}, {xi}, and {omega} in midrapidity Au+Au collisions at the Brookhaven National Laboratory Relativistic Heavy Ion Collider at {radical}(s{sub NN})=200 GeV. The yield of multistrange baryons per participant nucleon increases from peripheral to central collisions more rapidly than that of {lambda}, indicating an increase of the strange-quark density of the matter produced. The strange phase-space occupancy factor {gamma}{sub s} approaches unity for the most central collisions. Moreover, the nuclear modification factors of p, {lambda}, and {xi} are consistent with each other for 2<p{sub T}<5 GeV/c in agreement with a scenario of hadron formation frommore » constituent quark degrees of freedom.« less
  • We present the first statistically meaningful results from two-K{sub s}{sup 0} interferometry in heavy-ion collisions at {radical}s{sub NN} = 200 GeV. A model that takes the effect of the strong interaction into account has been used to fit the measured correlation function. The effects of single and coupled channels were explored. At the mean transverse mass <m{sub T}> = 1.07 GeV, we obtain the values R = 4.09 {+-} 0.46(stat) {+-} 0.31(sys) fm and {lambda} = 0.92 {+-} 0.23(stat) {+-} 0.13(sys), where R and {lambda} are the invariant radius and chaoticity parameters, respectively. The results are qualitatively consistent with m{submore » T} systematics established with pions in a scenario characterized by a strong collective flow.« less
  • We report the measurements of {Sigma}(1385) and {Lambda}(1520) production in p+p and Au+Au collisions at {radical}s{sub NN} = 200 GeV from the STAR Collaboration. The yields and the p{sub T} spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central Au+Au collisions. Our results indicate that there may be a time span between chemical and thermal freeze-out during which elastic hadronic interactions occur.
  • We report on the observed differences in production rates of strange and multistrange baryons in Au+Au collisions at {radical}s{sub NN} = 200 GeV compared to p+p interactions at the same energy. The strange baryon yields in Au+Au collisions, when scaled down by the number of participating nucleons, are enhanced relative to those measured in p+p reactions. The enhancement observed increases with the strangeness content of the baryon, and it increases for all strange baryons with collision centrality. The enhancement is qualitatively similar to that observed at the lower collision energy {radical}s{sub NN} = 17.3 GeV. The previous observations are formore » the bulk production, while at intermediate p{sub T},1 < p{sub T} < 4 GeV/c, the strange baryons even exceed binary scaling from p+p yields.« less
  • We present first measurements of the {phi}-meson elliptic flow (v{sub 2}(p{sub T})) and high-statistics p{sub T} distributions for different centralities from {radical}s{sub NN} = 200 GeV Au+Au collisions at RHIC. In minimum bias collisions the v{sub 2} of the {phi} meson is consistent with the trend observed for mesons. The ratio of the yields of the {Omega} to those of the {phi} as a function of transverse momentum is consistent with a model based on the recombination of thermal s quarks up to p{sub T} {approx} 4 GeV/c, but disagrees at higher momenta. The nuclear modification factor (R{sub CP}) ofmore » {phi} follows the trend observed in the K{sub S}{sup 0} mesons rather than in {Lambda} baryons, supporting baryon-meson scaling. These data are consistent with {phi} mesons in central Au+Au collisions being created via coalescence of thermalized s quarks and the formation of a hot and dense matter with partonic collectivity at RHIC.« less