Resonance form factors from finite-volume correlation functions with the external field method
High Energy Physics - Lattice
2022-09-19 v2 High Energy Physics - Phenomenology
Nuclear Theory
Abstract
A novel method for the extraction of form factors of unstable particles on the lattice is proposed. The approach is based on the study of two-particle scattering in a static, spatially periodic external field by using a generalization of the L\"uscher method in the presence of such a field. It is shown that the resonance form factor is given by the derivative of the resonance pole position in the complex plane with respect to the coupling constant to the external field. Unlike the standard approach, this proposal does not suffer from problems caused by the presence of the triangle diagram.
Cite
@article{arxiv.2205.11316,
title = {Resonance form factors from finite-volume correlation functions with the external field method},
author = {Jonathan Lozano and Ulf-G. Meißner and Fernando Romero-López and Akaki Rusetsky and Gerrit Schierholz},
journal= {arXiv preprint arXiv:2205.11316},
year = {2022}
}
Comments
36 pages, 10 figures. v2: reformulated introduction, added new figure 4, and minor changes. Conclusions unchanged