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Title: Charged and strange hadron elliptic flow in Cu+Cu collisions at {radical}{ovr s} = 2.4 and 200 GeV at the STAR detector.

Abstract

We present the results of an elliptic flow, v{sub 2}, analysis of Cu+Cu collisions recorded with the solenoidal tracker detector (STAR) at the BNL Relativistic Heavy Ion Collider at {radical}s{sub NN} = 62.4 and 200 GeV. Elliptic flow as a function of transverse momentum, v{sub 2}(p{sub T}), is reported for different collision centralities for charged hadrons h{sup {+-}} and strangeness-ontaining hadrons K{sub S}{sup 0}, {Lambda}, {Xi}, and {phi} in the midrapidity region |{eta}| < 1.0. Significant reduction in systematic uncertainty of the measurement due to nonflow effects has been achieved by correlating particles at midrapidity, |{eta}| < 1.0, with those at forward rapidity, 2.5 < |{eta}| < 4.0. We also present azimuthal correlations in p+p collisions at {radical}s = 200 GeV to help in estimating nonflow effects. To study the system-size dependence of elliptic flow, we present a detailed comparison with previously published results from Au+Au collisions at {radical}s{sub NN} = 200 GeV. We observe that v{sub 2}(p{sub T}) of strange hadrons has similar scaling properties as were first observed in Au+Au collisions, that is, (i) at low transverse momenta, p{sub T} < 2 GeV/c, v{sub 2} scales with transverse kinetic energy, m{sub T}-m, and (ii) at intermediate p{sub T},more » 2 < p{sub T} < 4 GeV/c, it scales with the number of constituent quarks, n{sub q}. We have found that ideal hydrodynamic calculations fail to reproduce the centrality dependence of v{sub 2}(p{sub T}) for K{sub S}{sup 0} and {Lambda}. Eccentricity scaled v{sub 2} values, v{sub 2}/{var_epsilon}, are larger in more central collisions, suggesting stronger collective flow develops in more central collisions. The comparison with Au+Au collisions, which go further in density, shows that v{sub 2}/{var_epsilon} depends on the system size, that is, the number of participants N{sub part}. This indicates that the ideal hydrodynamic limit is not reached in Cu+Cu collisions, presumably because the assumption of thermalization is not attained.« less

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC); National Science Foundation (NSF); EPSRC - United Kingdom; Polish Ministry of Science and Higher Education
OSTI Identifier:
1050169
Report Number(s):
ANL-HEP-PR-10-38
Journal ID: ISSN 0556-2813; PRVCAN; TRN: US1204549
DOE Contract Number:  
DE-AC02-06CH11357
Resource Type:
Journal Article
Journal Name:
Physical Review, C (Nuclear Physics)
Additional Journal Information:
Journal Volume: 81; Journal Issue: 4; Journal ID: ISSN 0556-2813
Country of Publication:
United States
Language:
ENGLISH
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BNL; HADRONS; HEAVY IONS; HYDRODYNAMICS; KINETIC ENERGY; PARTICLE RAPIDITY; QUARKS; THERMALIZATION; TRANSVERSE MOMENTUM; ION COLLISIONS

Citation Formats

Abelev, B I, Aggarwal, M M, Ahammed, Z, Alakhverdyants, A V, Alekseev, I, Bridgeman, A, Krueger, K, Spinka, H M, Underwood, D G, STAR Collaboration, Univ. of Illinois at Chicago), Panjab Univ.), Variable Energy Cyclotron Centre), Joint Inst. for Nuclear Res.), and Alikhanov Inst. for Theoretical and Experimental Physics). Charged and strange hadron elliptic flow in Cu+Cu collisions at {radical}{ovr s} = 2.4 and 200 GeV at the STAR detector.. United States: N. p., 2010. Web. doi:10.1103/PhysRevC.81.044902.
Abelev, B I, Aggarwal, M M, Ahammed, Z, Alakhverdyants, A V, Alekseev, I, Bridgeman, A, Krueger, K, Spinka, H M, Underwood, D G, STAR Collaboration, Univ. of Illinois at Chicago), Panjab Univ.), Variable Energy Cyclotron Centre), Joint Inst. for Nuclear Res.), & Alikhanov Inst. for Theoretical and Experimental Physics). Charged and strange hadron elliptic flow in Cu+Cu collisions at {radical}{ovr s} = 2.4 and 200 GeV at the STAR detector.. United States. https://doi.org/10.1103/PhysRevC.81.044902
Abelev, B I, Aggarwal, M M, Ahammed, Z, Alakhverdyants, A V, Alekseev, I, Bridgeman, A, Krueger, K, Spinka, H M, Underwood, D G, STAR Collaboration, Univ. of Illinois at Chicago), Panjab Univ.), Variable Energy Cyclotron Centre), Joint Inst. for Nuclear Res.), and Alikhanov Inst. for Theoretical and Experimental Physics). Fri . "Charged and strange hadron elliptic flow in Cu+Cu collisions at {radical}{ovr s} = 2.4 and 200 GeV at the STAR detector.". United States. https://doi.org/10.1103/PhysRevC.81.044902.
@article{osti_1050169,
title = {Charged and strange hadron elliptic flow in Cu+Cu collisions at {radical}{ovr s} = 2.4 and 200 GeV at the STAR detector.},
author = {Abelev, B I and Aggarwal, M M and Ahammed, Z and Alakhverdyants, A V and Alekseev, I and Bridgeman, A and Krueger, K and Spinka, H M and Underwood, D G and STAR Collaboration and Univ. of Illinois at Chicago) and Panjab Univ.) and Variable Energy Cyclotron Centre) and Joint Inst. for Nuclear Res.) and Alikhanov Inst. for Theoretical and Experimental Physics)},
abstractNote = {We present the results of an elliptic flow, v{sub 2}, analysis of Cu+Cu collisions recorded with the solenoidal tracker detector (STAR) at the BNL Relativistic Heavy Ion Collider at {radical}s{sub NN} = 62.4 and 200 GeV. Elliptic flow as a function of transverse momentum, v{sub 2}(p{sub T}), is reported for different collision centralities for charged hadrons h{sup {+-}} and strangeness-ontaining hadrons K{sub S}{sup 0}, {Lambda}, {Xi}, and {phi} in the midrapidity region |{eta}| < 1.0. Significant reduction in systematic uncertainty of the measurement due to nonflow effects has been achieved by correlating particles at midrapidity, |{eta}| < 1.0, with those at forward rapidity, 2.5 < |{eta}| < 4.0. We also present azimuthal correlations in p+p collisions at {radical}s = 200 GeV to help in estimating nonflow effects. To study the system-size dependence of elliptic flow, we present a detailed comparison with previously published results from Au+Au collisions at {radical}s{sub NN} = 200 GeV. We observe that v{sub 2}(p{sub T}) of strange hadrons has similar scaling properties as were first observed in Au+Au collisions, that is, (i) at low transverse momenta, p{sub T} < 2 GeV/c, v{sub 2} scales with transverse kinetic energy, m{sub T}-m, and (ii) at intermediate p{sub T}, 2 < p{sub T} < 4 GeV/c, it scales with the number of constituent quarks, n{sub q}. We have found that ideal hydrodynamic calculations fail to reproduce the centrality dependence of v{sub 2}(p{sub T}) for K{sub S}{sup 0} and {Lambda}. Eccentricity scaled v{sub 2} values, v{sub 2}/{var_epsilon}, are larger in more central collisions, suggesting stronger collective flow develops in more central collisions. The comparison with Au+Au collisions, which go further in density, shows that v{sub 2}/{var_epsilon} depends on the system size, that is, the number of participants N{sub part}. This indicates that the ideal hydrodynamic limit is not reached in Cu+Cu collisions, presumably because the assumption of thermalization is not attained.},
doi = {10.1103/PhysRevC.81.044902},
url = {https://www.osti.gov/biblio/1050169}, journal = {Physical Review, C (Nuclear Physics)},
issn = {0556-2813},
number = 4,
volume = 81,
place = {United States},
year = {2010},
month = {1}
}