Nuclear p⊥-broadening of Drell-Yan and quarkonium production from SPS to LHC

Abstract

Abstract The nuclear p⊥-broadening of Drell-Yan and quarkonium (J/ψ, Υ) production in πA and pA collisions is investigated. The world data follow a simple scaling from SPS to LHC energies, once the process-dependent color factors are properly taken into account, which allows for the extraction of the transport coefficient in cold nuclear matter. We find that $$ \hat{q}(x)\propto {x}^{-\alpha } $$ q ̂ x ∝ x − α with α = 0.25–0.30. The magnitude of the transport coefficient at x = 10−2 is $$ {\hat{q}}_0=0.051\;{\mathrm{GeV}}^2/\mathrm{fm} $$ q ̂ 0 = 0.051 GeV 2 / fm and $$ {\hat{q}}_0=0.075\;{\mathrm{GeV}}^2/\mathrm{fm} $$ q ̂ 0 = 0.075 GeV 2 / fm qˆ0 = 0.075 GeV2/fm, whether $$ Q\overline{Q} $$ Q Q ¯ pairs are assumed to be produced as color octet or color singlet states, respectively. The relation between nuclear broadening data and the (CT14) gluon density is also investigated.