Twist-3 T-odd fragmentation functions $G^{\perp }$ and ${\tilde{G}}^{\perp }$ in a spectator model

Abstract

We present a calculation of the twist-3 T-odd chiral-even fragmentation functions $G^{\perp }$ and ${\tilde{G}}^{\perp }$ 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 $G^{\perp }$, ${\tilde{G}}^{\perp }$ and the Collins function.

Comments: 8 pages, 3 figures, match the version published in PLB