%0 Journal Article
%A Shi, Yu-Ji
%A Seng, Chien-Yeah
%A Guo, Feng-Kun
%A Kubis, Bastian
%A Meißner, Ulf-G.
%A Wang, Wei
%T Two-meson form factors in unitarized chiral perturbation theory
%J Journal of high energy physics
%V 2021
%N 4
%@ 1029-8479
%C [Trieste]
%I SISSA
%M FZJ-2021-01776
%P 86
%D 2021
%X We present a comprehensive analysis of form factors for two light pseudoscalar mesons induced by scalar, vector, and tensor quark operators. The theoretical framework is based on a combination of unitarized chiral perturbation theory and dispersion relations. The low-energy constants in chiral perturbation theory are fixed by a global fit to the available data of the two-meson scattering phase shifts. Each form factor derived from unitarized chiral perturbation theory is improved by iteratively applying a dispersion relation. This study updates the existing results in the literature and explores those that have not been systematically studied previously, in particular the two-meson tensor form factors within unitarized chiral perturbation theory. We also discuss the applications of these form factors as mandatory inputs for low-energy phenomena, such as the semi-leptonic decays Bs → π+π−ℓ+ℓ− and the τ lepton decay τ → π−π0ντ, in searches for physics beyond the Standard Model.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000639403500001
%R 10.1007/JHEP04(2021)086
%U https://juser.fz-juelich.de/record/891856