Nuclear parton distributions — a DGLAP analysis

Abstract Nuclear parton distributions f A ( x, Q 2 ) are studied within a framework of the DGLAP evolution. Measurements of F A 2 / F D 2 in deep inelastic lA collisions, and Drell-Yan dilepton cross sections measured in pA collisions are used as constraints. Also conservation of momentum and baryon number is required. It is shown that the calculated Q 2 evolution of F Sn 2 / F C 2 agrees very well with the recent NMC data, and that the ratios R A f = f A / f are only moderately sensitive to the choice of a specific modern set of free parton distributions. For general use, we offer a numerical parametrization of R A f ( x , Q 2 ) for all parton flavours f in A > 2, and at 10 −6 ≤ x ≤ 1 and 2.25 GeV 2 ≤ Q 2 ≤ 10 4 GeV 2 .