Drell-Yan-like processes and duality

Abstract

We calculate the gauge invariant Drell-Yan-like hadron tensors. In connection with new COMPASS results, we propose the single spin asymmetry which probes gluon poles together with chiral-odd and time-odd functions. The relevant pion production as a particular case of Drell-Yan-like process has been discussed. For the meson-induced Drell-Yan process, we model an analog of the twist three distribution function, which is a collinear function in inclusive channel, by means of two non-collinear distribution amplitudes which are associated with exclusive channel. This modelling demonstrates the fundamental duality between different factorization regimes.