Chiral-odd GPDs in the bag model

Abstract

A study of chiral-odd generalized parton distributions (GPDs) of the nucleon is presented in the bag model demonstrating that in this model all four chiral-odd GPDs are non-zero contrary to other claims in literature. The bag model results for the GPDs $H_T^q(x,\hat{I}¾,t)$, $E_T^q(x,\hat{I}¾,t)$, ${\tilde{H}}_T^q(x,\hat{I}¾,t)$ agree with other models within a typical quark model accuracy. We present one of the few quark model calculations where polynomiality is satisfied and the sum rule $\int dx{\tilde{E}}_T^q(x,\hat{I}¾,t)=0$ holds. We confront our results with predictions from the large-$N_c$ limit, and with lattice QCD calculations. We conclude that the bag model successfully catches the main features of chiral-odd GPDs.

21 pages, 9 figures, 2 tables v2: minor corrections, references added