Testing universality of the Color Glass Condensate descriptions
Abstract
Perturbative Quantum Chromodynamics (pQCD) predicts that the small-
x
gluons in a hadron wavefunction should form a Color Glass Condensate (CGC), which has universal properties, which are the same for all hadrons or nuclei. Assuming this property, in this paper we cross relate the current CGC descriptions of the
ep
HERA data and
dAu
RHIC data. In particular, we use the quark dipole scattering amplitude recently proposed by Kharzeev, Kovchegov and Tuchin (KKT) to explain the high
p
T
particle suppression observed in
dAu
collisions at RHIC in our calculations of the proton and longitudinal structure functions. We present a detailed comparison between this parameterization and those proposed to describe the
ep
HERA data. We find out that, due to its peculiar dependence on the energy and dipole separation, the KKT parameterization is able to describe the experimental
ep
data only in a limited kinematical range of photon virtualities.