DOUBLE SPIN ASYMMETRY A_LT IN THE PRODUCTION OF PHOTONS, HADRONS, AND JETS

Abstract

We calculate the double spin asymmetry (DSA) A LT in proton-proton (pp) collisions for the production of photons, hadrons, and jets in the collinear twist-3 framework. These processes allows us for the first time to access a complete set of collinear twist-3 functions. We also give numerical estimates for the asymmetries of which photon production shows the most promise of a measurable effect. Furthermore, we comment on how these asymmetries would allow us to probe the gluon helicity down to as of yet unexplored x values, remark on the importance of these effects in determining the evolution of the Efremov-Teryaev-Qiu-Sterman (ETQS) function T F (x, x), and discuss their usefulness in resolving the true mechanism behind the large transverse single spin asymmetries (SSAs) measured in pp collisions.