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Title: Transverse momentum and centrality dependence of high-p{sub T} nonphotonic electron suppression in Au+Au collisions at {radical}{ovr s}{sub NN} = 200 GeV.

Abstract

The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of the inclusive yield of nonphotonic electrons, which arise dominantly from semileptonic decays of heavy flavor mesons, over a broad range of transverse momenta (1.2 < p{sub T} < 10 GeV/c) in p+p, d+Au, and Au+Au collisions at {radical}s{sub NN} = 200 GeV. The nonphotonic electron yield exhibits an unexpectedly large suppression in central Au+Au collisions at high p{sub T}, suggesting substantial heavy-quark energy loss at RHIC. The centrality and p{sub T} dependences of the suppression provide constraints on theoretical models of suppression.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC); National Science Foundation (NSF); Swiss NSF
OSTI Identifier:
964643
Report Number(s):
ANL-HEP-PR-09-56
Journal ID: ISSN 0031-9007; PRLTAO; TRN: US0903606
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; BNL; ELECTRONS; MESONS; SEMILEPTONIC DECAY; TRANSVERSE MOMENTUM

Citation Formats

Krueger, K., McClain, C. J., Spinka, H. M., Underwood, D. G., Abelev, B. I., Aggarwal, M. M., Ahammed, Z., Anderson, B. D., Arkhipkin, D., STAR Collaboration, High Energy Physics, Univ. of Illinois, Panjab Univ., Variable Energy Cyclotron Centre, Kent State Univ., and Particale Physics Lab. Transverse momentum and centrality dependence of high-p{sub T} nonphotonic electron suppression in Au+Au collisions at {radical}{ovr s}{sub NN} = 200 GeV.. United States: N. p., 2007. Web. doi:10.1103/PhysRevLett.98.192301.
Krueger, K., McClain, C. J., Spinka, H. M., Underwood, D. G., Abelev, B. I., Aggarwal, M. M., Ahammed, Z., Anderson, B. D., Arkhipkin, D., STAR Collaboration, High Energy Physics, Univ. of Illinois, Panjab Univ., Variable Energy Cyclotron Centre, Kent State Univ., & Particale Physics Lab. Transverse momentum and centrality dependence of high-p{sub T} nonphotonic electron suppression in Au+Au collisions at {radical}{ovr s}{sub NN} = 200 GeV.. United States. doi:10.1103/PhysRevLett.98.192301.
Krueger, K., McClain, C. J., Spinka, H. M., Underwood, D. G., Abelev, B. I., Aggarwal, M. M., Ahammed, Z., Anderson, B. D., Arkhipkin, D., STAR Collaboration, High Energy Physics, Univ. of Illinois, Panjab Univ., Variable Energy Cyclotron Centre, Kent State Univ., and Particale Physics Lab. Mon . "Transverse momentum and centrality dependence of high-p{sub T} nonphotonic electron suppression in Au+Au collisions at {radical}{ovr s}{sub NN} = 200 GeV.". United States. doi:10.1103/PhysRevLett.98.192301.
@article{osti_964643,
title = {Transverse momentum and centrality dependence of high-p{sub T} nonphotonic electron suppression in Au+Au collisions at {radical}{ovr s}{sub NN} = 200 GeV.},
author = {Krueger, K. and McClain, C. J. and Spinka, H. M. and Underwood, D. G. and Abelev, B. I. and Aggarwal, M. M. and Ahammed, Z. and Anderson, B. D. and Arkhipkin, D. and STAR Collaboration and High Energy Physics and Univ. of Illinois and Panjab Univ. and Variable Energy Cyclotron Centre and Kent State Univ. and Particale Physics Lab.},
abstractNote = {The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of the inclusive yield of nonphotonic electrons, which arise dominantly from semileptonic decays of heavy flavor mesons, over a broad range of transverse momenta (1.2 < p{sub T} < 10 GeV/c) in p+p, d+Au, and Au+Au collisions at {radical}s{sub NN} = 200 GeV. The nonphotonic electron yield exhibits an unexpectedly large suppression in central Au+Au collisions at high p{sub T}, suggesting substantial heavy-quark energy loss at RHIC. The centrality and p{sub T} dependences of the suppression provide constraints on theoretical models of suppression.},
doi = {10.1103/PhysRevLett.98.192301},
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}
}
  • The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of the inclusive yield of nonphotonic electrons, which arise dominantly from semileptonic decays of heavy flavor mesons, over a broad range of transverse momenta (1.2<p{sub T}<10 GeV/c) in p+p, d+Au, and Au+Au collisions at {radical}(s{sub NN})=200 GeV. The nonphotonic electron yield exhibits an unexpectedly large suppression in central Au+Au collisions at high p{sub T}, suggesting substantial heavy-quark energy loss at RHIC. The centrality and p{sub T} dependences of the suppression provide constraints on theoretical models of suppression.
  • We study the energy dependence of the transverse momentum (p{sub T}) spectra for charged pions, protons and anti-protons for Au+Au collisions at {radical}s{sub NN} = 62.4 and 200 GeV. Data are presented at mid-rapidity (|y| < 0.5) for 0.2 < p{sub T} < 12 GeV/c. In the intermediate p{sub T} region (2 < p{sub T} < 6 GeV/c), the nuclear modification factor is higher at 62.4 GeV than at 200 GeV, while at higher p{sub T} (p{sub T} > 7 GeV/c) the modification is similar for both energies. The p/{pi}{sup +} and {bar p}/{pi}{sup -} ratios for central collisions atmore » {radical}s{sub NN} = 62.4 GeV peak at p{sub T} {approx_equal} 2 GeV/c. In the p{sub T} range where recombination is expected to dominate, the p/{pi}{sup +} ratios at 62.4 GeV are larger than at 200 GeV, while the {bar p}/{pi}{sup -} ratios are smaller. For p{sub T} > 2 GeV/c, the {bar p}/{pi}{sup -} ratios at the two beam energies are independent of p{sub T} and centrality indicating that the dependence of the {bar p}/{pi}{sup -} ratio on p{sub T} does not change between 62.4 and 200 GeV. These findings challenge various models incorporating jet quenching and/or constituent quark coalescence.« less
  • We have measured transverse momentum distributions of charged hadrons produced in Au+Au collisions at {radical}{ovr S{sub NN}} = 62.4 GeV. The spectra are presented for transverse momenta 0.25 < p{sub T} < 4.5 GeV/c, in a pseudo-rapidity range of 0.2 < {eta} < 1.4. The nuclear modification factor R{sub AA} is calculated relative to p+p data at the same collision energy as a function of collision centrality. For 2 < p{sub T} < 4.5 GeV/c, R{sub AA} is found to be significantly larger than in Au+Au collisions at {radical}{ovr S{sub NN}} = 130 and 200 GeV. In contrast to themore » large change in R{sub AA}, we observe a very similar centrality evolution of the p{sub T} spectra at {radical}{ovr S{sub NN}} = 62.4 GeV and 200 GeV. The dynamical origin of this surprising factorization of energy and centrality dependence of particle production in heavy ion collisions remains to be understood.« less
  • We present first measurements of the pseudorapidity and azimuth ({eta}, {phi}) bin-size dependence of event-wise mean transverse-momentum <p{sub T}> fluctuations for Au-Au collisions at {radical}s{sub NN} = 200 GeV. We invert that dependence to obtain p{sub t} autocorrelations on differences ({eta}{sub {Delta}}, {phi}{sub {Delta}}) interpreted to represent velocity/temperature distributions on ({eta}, {phi}). The general form of the autocorrelations suggests that the basic correlation mechanism is parton fragmentation. The autocorrelations vary rapidly with collision centrality, which suggests that fragmentation is strongly modified by a dissipative medium in the more central Au-Au collisions relative to peripheral or p-p collisions.