Boer-Mulders function of the pion in the MIT bag model
  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. 
Zhun Lu, Bo-Qiang Ma, Jiacai Zhu
hep-ph hep-ex