Scaling Variable for Nuclear Shadowing in Deep-Inelastic Scattering∗

A new scaling variable is introduced in terms of which nuclear shadowing in deepinelastic scattering is universal, i.e. independent of A, Q2 and x. This variable can be interpreted as a measure of the number of gluons probed by the hadronic fluctuations of a virtual photon during their lifetime. The shadowing correction grows at small x substantially less steeply than is suggested by the eikonal approximation. This results from the fact that shadowing is dominated by soft rather than hard interactions. Based on the talk presented by B. Kopeliovich at the Workshop on Particle Theory and Phenomenology, Ames, Iowa, 1995 On leave from the Joint Institute for Nuclear Research, Laboratory of Nuclear Problems, Dubna, 141980 Moscow Region, Russia. E-mail: [email protected]