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

Abstract

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 $c\bar{c}$ pair. If $J/ψ$'s are not produced {\it via} a $2 \to 1$ 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 $d$Au collisions at $\sqrtsNN=200\mathrm{GeV}$, using several shadowing parametrisations.

6 pages, 1 table, 3 figures, Submitted to J. Phys. G, talk given at the International Conference on Strangeness in Quark Matter (SQM2009), Buzios, Brasil, Sep. 27 - Oct. 2, 2009