Leptons from heavy-quark semileptonic decay in pA collisions within the CGC framework

Abstract

We study single lepton production from semileptonic decays of heavy flavor hadrons (D, B → l) in pp and pA collisions at RHIC and the LHC within the saturation/Color-Glass-Condensate (CGC) framework. Using the gluon distribution function obtained with the dipole amplitude, whose energy dependence is described by the Balitsky-Kovchegov equation with running coupling effect, we compute the transverse-momentum (p ⊥ ) spectra of the lepton yields at mid and forward rapidities. We find that a large fraction of leptons at low p ⊥ stems from the saturation regime of the incoming gluons in the target, especially in pA collisions at the LHC. The resultant p ⊥ spectra is slightly harder than the data, but the nuclear modification factor seems consistent with the data within some uncertainty. We also update the nuclear modification factors for J/ψ and D meson at the LHC energy.

Production of muons from heavy-flavour hadron decays in p–Pb collisions at sNN=5.02 TeV

“…The same model is able to describe both the p T -differential R pPb of electrons from heavy-flavour hadron decays measured at midrapidity with ALICE, which is also consistent with unity within uncertainties [51], and the enhancement seen at backward rapidity in d-Au collisions at √ s NN = 200 GeV for muons from heavy-flavour hadron decays [72]. Theoretical calculations based on the Colour Glass Condensate model [74] predict that for the rapidity interval 2.5 < y cms < 3.53, the R pPb of muons from charm-hadron decays for the interval 0 < p T < 4 GeV/c increases with increasing p T from about 0.6 to 0.85. This predicted R pPb is slightly smaller than that reported here for muons from heavy-flavour hadron decays, 3 although for a slightly different rapidity interval.…”

Heavy-flavour production in high-energy d-Au and p-Pb collisions

“…This will also allow one to discriminate among our predictions and the ones of the other models, which don't assume the formation of a hot medium, but involve only cold nuclear matter effects [59][60][61][62]. We leave such an issue for future publications.…”

Forward J/ψ production at high energy: Centrality dependence and mean transverse momentum

“…In addition, J/ψ production has been the subject of many experimental studies at the LHC, both in proton-proton [1][2][3][4][5][6][7] and in proton-nucleus [8][9][10][11][12] collisions. This provides a lot of data to confront with nuclear effects predicted by various theoretical models, both in the Color Glass Condensate (CGC) framework [13][14][15][16][17] and as constraints for nuclear parton distribution functions [18] and energy loss in cold nuclear matter [19][20][21][22].…”