Helicity Flip in Diffractive DIS

Abstract

I review new results on s-channel helicity nonconservation (SCHNC) in diffractive DIS. I discuss how by virtue of unitarity diffractive DIS gives rise to spin structure functions which were believed to vanish at x << 1. These include tensor polarization of sea quarks in the deuteron, strong breaking of the Wandzura-Wilczek relation and demise of the Burkhardt-Cottingham sum rule.

6 pages, 3 figures. The invited talk at QCD & Multiparticle Production, XXIX International Symposium on Multiparticle Dynamics (ISMD99), August 9-13, 1999. Brown University, Providence, RI 02912, USA