Generalised parton distributions of the pion in partially-quenched chiral perturbation theory

TL;DR

This paper uses partially-quenched chiral perturbation theory to analyze pion matrix elements related to generalized parton distributions, aiding lattice QCD extrapolations to physical conditions.

Contribution

It provides new theoretical results for pion matrix elements in SU(2) and SU(4|2) frameworks, including finite volume effects, to improve lattice QCD analyses.

Findings

Results at infinite volume for SU(2) and SU(4|2) theories.

Finite volume effects are characterized and addressed.

Results facilitate more accurate lattice extrapolations.

Abstract

We consider the pion matrix elements of the isoscalar and isovector combinations of the vector and tensor twist-two operators that determine the moments of the various pion generalised parton distributions. Our analysis is performed using partially-quenched chiral perturbation theory. We work in the SU(2) and SU(4|2) theories and present our results at infinite volume and also at finite volume where some subtleties arise. These results are useful for extrapolations of lattice calculations of these matrix elements at small momentum transfer to the physical regime.