Search

Abstract: We present various predictions for the upcoming collisions at within the color glass condensate (CGC) formalism, including single inclusive charged hadron production, single inclusive prompt photon production, direct photon production, charged hadron multiplicity distribution and photon–hadron azimuthal correlations. Using the running-coupling Balitsky–Kovchegov evolution equation for calculating various observables, we show that the main source of uncertainties is due to less constrained initial nuclear saturation scale. This gives rise to rather large theoretical uncertainties for nuclear modification factor at the LHC. Nevertheless, we propose a simple scheme in which one can still test the main dynamics of the CGC/saturation in collisions at the LHC. [Copyright &y& Elsevier]

Abstract: We show that pQCD factorization incorporated with pre-hadronization energy-loss effect naturally leads to flatness of the nuclear modification factor for produced hadrons at high transverse momentum . We consider two possible scenarios for the pre-hadronization: In scenario 1, the produced gluon propagates through dense QCD medium and loses energy. In scenario 2, all gluons first decay to quark–antiquark pairs and then each pair loses energy as propagating through the medium. We show that the estimates of the energy-loss in these two different models lead to very close values and is able to explain the suppression of high- hadrons in nucleus–nucleus collisions at RHIC. We show that the onset of the flatness of for the produced hadron in central collisions at midrapidity is about and 25 GeV at RHIC and the LHC energies, respectively. We show that the smallness ( ) and the high- flatness of obtained from the factorization supplemented with the Balitsky–Kovchegov (BK) equation is rather generic and it does not strongly depend on the details of the BK solutions. We show that energy-loss effect reduces the nuclear modification factor obtained from the factorization about 30–50% at moderate . [Copyright &y& Elsevier]