New parameterization of the resonant production amplitudes near an inelastic threshold

TL;DR

This paper introduces a new, more accurate parameterization for resonant production amplitudes near inelastic thresholds, improving upon the commonly used Flatte formula and aiding in the analysis of meson interactions and scalar resonances.

Contribution

It derives new formulae for resonant amplitudes that are more precise than the Flatte formula and proposes a unitary parameterization consistent with the Watson theorem.

Findings

New formulae improve accuracy of resonance analysis

Application to scalar mesons like a0(980) and f0(980)

Enhanced data analysis methods for meson interactions

Abstract

New formulae for the resonant scattering and the production amplitudes near an inelastic threshold are derived. It is shown that the Flatte formula, frequently used in experimental analyses, is not sufficiently accurate. Its application to data analysis can lead to a substantial distortion of the effective mass spectra and of the resonance pole positions. A unitary parameterization, satisfying a generalized Watson theorem for the production amplitudes, is proposed. It can be easily applied to study production processes, multichannel meson-meson interactions and the resonance properties, including among others the scalar resonances a0(980) and f_0(980).