Evidence for excess pions in nuclei

Abstract

We analize two reactions: the electroproduction at small x and the Drell-Yan production by protons on nuclei. We show that nuclear shadowing in electroproduction is larger if the virtuality of inter- mediate hadrons is properly taken into account. In the Drell-Yan production, initial state interactions of fast partons are included. With this input, the excess pion contribution improves the description of data for both reactions.

Comments: Latex, 11 pages, 2 PS figures compressed and uuencoded