Resonance form factors from finite-volume correlation functions with the external field method

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 Lüscher met...

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Bibliographic Details
Main Authors: Lozano, Jonathan, Meißner, Ulf-G., Romero-López, Fernando, Rusetsky, Akaki, Schierholz, Gerrit
Other Authors: Massachusetts Institute of Technology. Center for Theoretical Physics
Format: Article
Language:English
Published: Springer Berlin Heidelberg 2022
Online Access:https://hdl.handle.net/1721.1/145940
Description
Summary: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 Lüscher 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.