T-odd transverse momentum dependent gluon fragmentation functions in a spectator model

TL;DR

This paper models T-odd gluon fragmentation functions for a spin-1/2 hadron using a spectator model, providing analytical expressions and numerical results for their dependence on momentum variables.

Contribution

It introduces a spectator model calculation for T-odd gluon TMD fragmentation functions, including analytical formulas and numerical analysis.

Findings

Two of four one-loop diagrams significantly contribute to the fragmentation functions.

Analytical expressions for all four T-odd gluon TMD fragmentation functions are derived.

Numerical results show the z- and k_T-dependence of the fragmentation functions.

Abstract

We present a model calculation of the T-odd transverse momentum dependent (TMD) gluon fragmentation functions for a spin-1/2 hadron. Our model is based on the postulation that a time-like off-shell gluon can fragment into a hadron and a single spectator particle, which is considered to be on-shell. We consider the effect of the gluon exchange to calculate all necessary one-loop diagrams for the gluon-gluon correlation functions. Two out of four one-loop diagrams give sizeable contributions to the fragmentation functions. We obtain analytical expressions for the four T-odd TMD fragmentation functions of the gluon. We also provide numerical results on the z-dependence and $k_T$-dependence of the fragmentation functions.