TY  - JOUR
AU  - Shi, Yu-Ji
AU  - Seng, Chien-Yeah
AU  - Guo, Feng-Kun
AU  - Kubis, Bastian
AU  - Meißner, Ulf-G.
AU  - Wang, Wei
TI  - Two-meson form factors in unitarized chiral perturbation theory
JO  - Journal of high energy physics
VL  - 2021
IS  - 4
SN  - 1029-8479
CY  - [Trieste]
PB  - SISSA
M1  - FZJ-2021-01776
SP  - 86
PY  - 2021
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000639403500001
DO  - DOI:10.1007/JHEP04(2021)086
UR  - https://juser.fz-juelich.de/record/891856
ER  -