Gauge invariance, gluonic poles and single spin asymmetry in Drell-Yan processes

Abstract

We explore the electromagnetic gauge invariance of the hadron tensor of the Drell-Yan process with one transversely polarized hadron. The special role is played by the contour gauge for gluon fields. The prescription for the gluonic pole in the twist 3 correlator is related to causality property and compared with the prescriptions for exclusive hard processes. As a result we get the extra contributions, which naively do not have an imaginary phase. The single spin asymmetry for the Drell-Yan process is accordingly enhanced by the factor of two.

5 pages, 1 figure; Contributed to The 19th International Spin Physics Symposium, Sept 27 - Oct 2, 2010, Juelich, Germany

References in corpus (3)

• QCD factorization of exclusive processes beyond leading twist: gamma*T -> rhoT impact factor with twist three accuracy
• Gauge invariance, causality and gluonic poles
• Non-Universality and Evolution of the Sivers Function

Cited by in corpus (3)

• New contributions to gluon poles in direct photon production
• Gauge invariance and gluon poles for direct photon production
• Factorization theorem, gluon poles and new contributions in semi-inclusive processes