Testing universality of the color glass condensate descriptions
Instituto de Física, Universidade de São Paulo, C.P. 66318, 05315-970, São Paulo, SP, Brazil
2 High and Medium Energy Group (GAME), Instituto de Física e Matemática, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-900, Pelotas, RS, Brazil
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Perturbative quantum chromodynamics 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 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.
© Springer-Verlag, 2005