Boer-Mulders function of the pion in the MIT bag model

TL;DR

This paper calculates the Boer-Mulders function of the pion using the MIT bag model, incorporating gauge link effects via one-gluon exchange, and compares results with spectator models.

Contribution

It introduces a novel application of the MIT bag model to compute the pion's Boer-Mulders function, including both helicity flip contributions and gauge link effects.

Findings

The MIT bag model produces a non-zero Boer-Mulders function for the pion.

Results are consistent with those from spectator models.

The model highlights the importance of both helicity flip contributions.

Abstract

We apply the MIT bag model to study the Boer-Mulders function of the pion, a $T$-odd function that describes the transverse polarization distribution of the quark inside the pion. We simulate the effect of the gauge link through the "one-gluon-exchange" approximation. We consider both the quark helicity nonflip and double-flip contributions. The result in the MIT bag model is compared with those in the spectator models.