Nuclear transverse momentum broadening in the color dipole approach at the LHC regime

Abstract

Abstract Transverse momentum broadening of a parton propagating through a large nucleus is evaluated in the color dipole approach using different models for the dipole cross section or unintegrated gluon distribution, which lead to different values of the coefficient C F ( 0 , s ) . Numerical calculations are compared to data extracted from LHCb, ALICE and PHENIX experiments for the nuclear broadening of J/ψ mesons. We find that different models which describe the small-x data predict values of nuclear broadening of transverse momentum that agree reasonably well with experiment. The centrality dependence was also analysed and the models are consistent with the ALICE measurements. Available experimental results, however, are not able to clearly distinguish the performance of the considered models.