Nuclear enhanced power corrections to DIS structure functions

We calculate nuclear enhanced power corrections to structure functions meas ured in deeply inelastic lepton-nucleus scattering in Quantum Chromodynamic s (QCD). We find that the nuclear medium enhanced power corrections at orde r of O(alpha (s)/Q(2)) enhance the longitudinal structure function F-L and suppress the transverse structure function F-1. We demonstrate that strong nuclear effects in sigma (A)/sigma (D) and R-A/R-D, recently observed by HE RMES Collaboration, can be explained in terms of the nuclear enhanced power corrections. (C) 2001 Published by Elsevier Science B.V.