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

TL;DR

This paper examines the uncertainties in extracting the J/psi absorption cross section in cold nuclear matter, emphasizing the effects of shadowing and nuclear absorption, and analyzing experimental data with various shadowing models.

Contribution

It provides a detailed analysis of how different assumptions about J/psi production mechanisms affect the determination of nuclear absorption cross sections.

Findings

Differences in absorption cross-section fits depend on the production process assumptions.

Experimental uncertainties and correlations significantly influence the extraction of the cross section.

Various shadowing parametrizations lead to different interpretations of the data.

Abstract

We investigate the cold nuclear matter effects on $J/\psi$ 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 $J/\psi$'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.