The scale dependence of nuclear parton distributions f_A(x,Q~2) is studied within a framework of lowest order leading-twist DGLAP evolution. We use the NMC and E665 measurements of nuclear functions in deep inelastic lA collisions, and the E772 measurements of Drell-Yan dilepton cross sections in pA collisions as constraints when extracting the nuclear parton distributions at an initial scale Q_o~2 for the DGLAP-evolution. Also conservation of momentum and baryon number are required. In particular, we show that the calculated Q~2 evolution of F_2~Sn/F_2~C agrees very well with the recent NMC data. We also show that the obtained ratios R-f~A=f_A/f are only moderately sensitive to the choice of a specific modern set of free parton distributions. Finally, for general use, we offer a numerical parametrization of R_f~A(x.Q~2) for all parton flavours f in A>2, and at 10~-6 <= x<= 1 and 2.25 GeV~2<=Q~2<=10~4GeV~2.
展开▼
