Cold nuclear modifications at RHIC and LHC

We use recent nuclear parton distributions, among them the Hirai — Kumano — Nagai (HKN) and Eskola — Paukkunen — Salgado (EPS08) parameterizations, in our pQCD-improved parton model to calculate the nuclear modification factor, R AA′ (p T ), at RHIC and at the LHC. At RHIC, the deuteron-gold nuclear modification factor for pions, measured at p T ≥ 10 GeV/c in central collisions, appears to deviate more from unity than the model results. The slopes of the calculated R dAu (p T ) are similar to the slopes of the PHENIX pion and photon data. At LHC, without final-state effects we see a small enhancement of R dPb (p T ) in the transverse momentum range 10 GeV/c ≥ p T ≥ 100 GeV/c for most parameterizations. The inclusion of final-state energy loss will reduce the R dPb (p T ) values.