Instantons and Single Spin Asymmetries

Abstract

A new mechanism for single spin asymmetries in strong interaction is proposed. It is based on instanton-induced nonperturbative chromomagnetic quark-gluon interaction. We estimate the contribution of this interaction to single spin asymmetry in quark-quark scattering. It is shown, that interference between quark spin-flip amplitude induced by instantons and spin-nonflip amplitude, which is related to nonperturbative two gluon exchange, gives a large value for a single spin asymmetry. Due to strong increasing of the instanton-induced spin-flip amplitude with energy, this asymmetry does not vanish at high energies.

Comments: 7 pages, Latex, 2 figures. To appear in Proc. Workshop ``Physics with Polarized Protons at HERA'' August 1997,DESY-Zeuthen