The axial-vector form factor of the nucleon in a finite box
Abstract
We consider the axial-vector form factor of the nucleon in a finite box. Starting from the chiral Lagrangian with nucleon and Delta-isobar degrees of freedom, we address, at the one-loop level, the impact of two types of finite-volume effects. On the one hand, there are the implicit effects from the in-box values of the nucleon and Delta-isobar masses. On the other hand, there are the explicit effects caused by computing the in-box loop integrals with the values of the nucleon and Delta-isobar masses obtained in the infinite-volume limit. Selected numerical results are shown for three lattice ensembles. We show that the implicit effects dominate the in-box form factor. Our results are presented in terms of a set of basis functions that generalize the Passarino-Veltman reduction scheme to the finite-box case, such that only scalar loop integrals have to be performed. The techniques we developed are more generally relevant for lattice studies of hadronic quantities.
Keywords
Cite
@article{arxiv.2504.11902,
title = {The axial-vector form factor of the nucleon in a finite box},
author = {Felix Hermsen and Tobias Isken and Matthias F. M. Lutz and Rob G. E. Timmermans},
journal= {arXiv preprint arXiv:2504.11902},
year = {2026}
}
Comments
36 pages, 2 figures and 2 tables, revised version in print