Identified particles at large transverse momenta in STAR in Au+Au collisions @ sqrt(s_NN) = 200 GeV

Abstract

We report measurements of the ratios of identified hadrons (pi,K,p,Lambda) in Au+Au collisions at sqrt(s_NN) = 200 GeV as a function of both collision centrality and transverse momentum (p_T). Ratios of anti-baryon to baryon yields are independent of p_T within 2<p_T <6 GeV/c indicating that, for such a range, our measurements are inconsistent with theoretical pQCD calculations predicting a decrease due to a stronger contribution from valence quark scattering. For both strange and non-strange species, a strong baryon enhancement relative to meson yields is observed as a function of collision centrality in this intermediate p_T region, leading to p/pi and Lambda/K ratios greater than unity. The nuclear modification factor, R_cp (central relative to peripheral collisions), is used to illustrate the interplay between jet quenching and hadron production. The physics implications of these measurements are discussed with reference to different theoretical models.

arXiv comment5 pages, 4 figures. Proceedings of Quark Matter 2004 Conference, Jan 2004, Oakland, USA. Submitted to Journal of Physics G

References in corpus (13)

• Suppression of Hadrons with Large Transverse Momentum in Central Au+Au Collisions at $sqrt {s sub {sub {NN}}}_ = 130 GeV
• Identified Charged Particle Spectra and Yields in Au+Au Collisions at sqrt(s_NN) = 200 GeV
• Transverse momentum and collision energy dependence of high $p_T$ hadron suppression in Au+Au collisions at ultrarelativistic energies
• The STAR Time Projection Chamber: A Unique Tool for Studying High Multiplicity Events at RHIC
• Hadron production in heavy ion collisions: Fragmentation and recombination from a dense parton phase
• Particle-type dependence of azimuthal anisotropy and nuclear modification of particle production in Au+Au collisions at s(NN)**(1/2) = 200-GeV
• Parton coalescence at RHIC
• High $p_T$ Azimuthal Asymmetry in Non-central A+A at RHIC
• Transverse flow and hadro-chemistry in Au+Au collisions at \sqrt{s_{NN}}=200 GeV
• Mid-rapidity $\Lambda$ and $\bar{\Lambda }$ Production in Au+Au Collisions at $\sqrt{s_{{}_{NN}}}=130$ GeV
• Identified Charged Particles in Quark and Gluon Jets
• High-p_T Pion Quenching versus anti+Baryon Enhancement in Nucleus-Nucleus Collisions
• High Transverse Momentum Results from the STAR Collaboration

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