On the theoretical and experimental uncertainties in the extraction of the J/ absorption cross section in cold nuclear matter

We investigate the cold nuclear matter effects on J/ψ production, whose understanding is fundamental to study the quark-gluon plasma. Two of these effects are of particular relevance: the shadowing of the parton distributions and the nuclear absorption of the cc̄ pair. If J/ψ’s are not produced via a 2→ 1 process as suggested by recent theoretical works, one has to modify accordingly the way to compute the nuclear shadowing. This naturally induces differences in the absorption cross-section fit to the data. A careful analysis of these differences however requires taking into account the experimental uncertainties and their correlations, as done in this work for dAu collisions at √ sNN = 200 GeV, using several shadowing parametrisations. PACS numbers: 25.75.Dw, 25.75.-q, 24.85.+p, 21.60.Ka