Pion, kaon, proton and anti-proton transverse momentum distributions from p+p and d+Au collisions at root(NN)-N-S=200GeV
Published in:
Physics Letters B 616,1-2 (2005) 8-16;
Abstract
Identified mid-rapidity particle spectra of pi(+/-), K+/-, and p((p) over bar) from 200 GeV p + p and d + Au collisions are reported. A time-of-flight detector based on multi-gap resistive plate chamber technology is used for particle identification. The particle-species dependence of the Cronin effect is observed to be significantly smaller than that at lower energies. The ratio of the nuclear modification factor (R-dAu) between protons (p + (p) over bar) and charged hadrons (h) in the transverse momentum range 1.2 < p(T) < 3.0 GeV/c is measured to be 1.19 +/- 0.05(stat) +/- 0.03(syst) in minimum-bias collisions and shows little centrality dependence. The yield ratio of (p + (p) over bar)/h in minimum-bias d + Au collisions is found to be a factor of 2 lower than that in Au + Au collisions, indicating that the Cronin effect alone is not enough to account for the relative baryon enhancement observed in heavy ion collisions at RHIC. (c) 2005 Elsevier B.V. All rights reserved.
Keywords
resistive plate chambers;; time projection chamber;; plus au;; hadron;; star;; dependence;; model;; qcd
Date of this Version
January 2005