TMDs in the bag model
  Leading and subleading twist transverse momentum dependent parton distribution functions (TMDs) are studied in a quark model framework provided by the bag model. A complete set of relations among different TMDs is derived, and the question is discussed how model-(in)dependent such relations are. A connection of the pretzelosity distribution and quark orbital angular momentum is derived. 
H. Avakian, A. V. Efremov, P. Schweitzer
hep-ph hep-ex nucl-th