Twist-3 T-odd fragmentation functions G⊥ and G˜⊥ in a spectator model

Abstract We present a calculation of the twist-3 T-odd chiral-even fragmentation functions G ⊥ and G ˜ ⊥ using a spectator model. We consider the effect gluon exchange to calculate all necessary one-loop diagrams for the quark–quark and quark–gluon–quark correlation functions. We find that the gluon loops corrections generate non-zero contribution to these two fragmentation function. We numerically calculate their half- k T moments by integrating over the transverse momentum and also verify the equation of motion relation among G ⊥ , G ˜ ⊥ and the Collins function.