Global reanalysis of nPDFs

Abstract

In this talk, we present the results from our recent global reanalysis of nuclear parton distribution functions (nPDFs), where the DGLAP-evolving nPDFs are constrained by nuclear hard process data from deep inelastic $l+A$ scattering (DIS) and the Drell-Yan (DY) process in $p+A$ collisions, and by sum rules. The main improvements over our earlier work {\em EKS98} are the automated $\chi^2$ minimization, better controllable fit functions and possibility for error estimates. The obtained 16-parameter fit to N=514 datapoints is good, $\chi^2/{\rm d.o.f}=0.82$. Fit quality comparison and the error estimates obtained show that the old {\em EKS98} parametrization is fully consistent with the present automated reanalysis. Comparison with other global nPDF analyses is presented as well. Within the DGLAP framework we also discuss the possibility of incorporating a clearly stronger gluon shadowing, which is suggested by the RHIC BRAHMS data from d+Au collisions.