Impact-parameter dependence of the nuclear modification ofJ/ψproduction ind+Au collisions atsNN=200GeV

Abstract

The centrality dependence of $\sqrt{{s}_{\mathit{NN}}}$ $=$ 200 GeV $d+\mathrm{Au}$ $J/\ensuremath{\psi}$ data, measured in 12 rapidity bins that span $\ensuremath{-}2.2<y<2.4$, has been fitted using a model containing an effective absorption cross section combined with EPS09 NLO shadowing. The centrality dependence of the shadowing contribution was allowed to vary nonlinearly, employing a variety of assumptions, in an effort to explore the limits of what can be determined from the data. The impact parameter dependencies of the effective absorption cross section and the shadowing parametrization are sufficiently distinct to be determined separately. It is found that the onset of shadowing is a highly nonlinear function of impact parameter. The mid and backward rapidity absorption cross sections are compared with lower energy data and, for times of 0.05 fm/$c$ or greater, data over a broad range of collision energies and rapidities are well described by a model in which the absorption cross section depends only on time spent in the nucleus.