Sivers and Boer-Mulders functions in Light-Cone Quark Models

TL;DR

This paper models the Sivers and Boer-Mulders functions using light-cone quark models with single-gluon exchange, showing dominant orbital angular momentum interference effects and good agreement with phenomenological data.

Contribution

It introduces a light-cone quark model approach to calculate naive-time-reversal-odd quark distributions incorporating final-state interactions.

Findings

Sivers function dominated by S- and P-wave interference

Boer-Mulders function significantly influenced by P- and D-wave interference

Model predictions align well with existing phenomenological parametrizations

Abstract

Results for the naive-time-reversal-odd quark distributions in a light-cone quark model are presented. The final-state interaction effects are generated via single-gluon exchange mechanism. The formalism of light-cone wave functions is used to derive general expressions in terms of overlap of wave-function amplitudes describing the different orbital angular momentum components of the nucleon. In particular, the model predictions show a dominant contribution from S- and P-wave interference in the Sivers function and a significant contribution also from the interference of P and D waves in the Boer-Mulders function. The favourable comparison with existing phenomenological parametrizations motivates further applications to describe azimuthal asymmetries in hadronic reactions.