The scale dependent nuclear effects in parton distributions
for practical applications
1 Department of Physics, University of
Jyväskylä, P.O.Box 35, FIN-40351 Jyväskylä, Finland
2 Departamento de Física de Partículas, Universidade de Santiago de Compostela, E-15706 Santiago de Compostela, Spain
Received: 10 August 1998 / Published online: 27 April 1999
The scale dependence of the ratios of parton distributions in a proton of a nucleus A and in the free proton, RiA(x,Q2)=fi/A(x,Q2)/fi(x,Q2), is studied within the framework of the lowest order leading-twist DGLAP evolution. By evolving the initial nuclear distributions obtained with the GRV-LO and CTEQ4L sets at a scale Q02, we show that the ratios RiA(x,Q2) are only moderately sensitive to the choice of a specific modern set of free parton distributions. We propose that to a good first approximation, this parton distribution set-dependence of the nuclear ratios RiA(x,Q2) can be neglected in practical applications. With this result, we offer a numerical parametrization of RiA(x,Q2) for all parton flavours i in any A>2, and at any and any for computing cross sections of hard processes in nuclear collisions.