Identified mid-rapidity particle spectra of π±, K±, and p(pˉ)
Nearby in the stack
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 (
RdAu
) between protons
(p+pˉ)
and charged hadrons (
h
) in the transverse momentum range
1.2<pT<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+pˉ)/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.