Radiative decays of hadronic molecules

TL;DR

This paper investigates the radiative decays of scalar mesons, particularly f0(980), to determine their molecular nature, providing theoretical predictions and comparing them with experimental data.

Contribution

It offers a detailed theoretical analysis of radiative decay widths of scalar mesons within the molecule model, including finite-range corrections and gauge invariance considerations.

Findings

Predicted decay widths support the molecular interpretation of f0(980)

Finite-range corrections significantly affect two-photon decay calculations

Experimental data on f0(980) decay align with the molecule model

Abstract

It is argued that radiative decays of scalars a0/f0(980) can serve as a decisive tool in establishing the nature of the latter. In particular, predictions for the widths of the radiative decays S->gamma V (S=a0/f0(980), V=omega/rho/gamma) are given in the framework of the molecule model of the scalars. Finite-range corrections are discussed in detail for the two-gamma decays of hadronic molecules, with a special attention payed to the interplay of various scales involved in the problem and to the gauge invariance of the amplitude. The results are applied to the two-photon decay of the f0(980), and the existing experimental data on this decay are argued to support the molecule assignment for the scalar f0(980).