Dynamics of strong and radiative decays of Ds mesons

TL;DR

This paper models the strong and radiative decays of Ds mesons using coupled-channel dynamics and chiral effective theory, providing insights into their masses, decay widths, and the role of light vector mesons.

Contribution

It introduces a coupled-channel chiral approach to describe Ds mesons and calculates their decay properties, including small chiral corrections and the significance of light vector mesons.

Findings

Ds mesons are generated by coupled-channel dynamics.

Chiral corrections are small, around order Q_χ^2.

Decay widths are about 140 keV, matching experimental data.

Abstract

The positive parity scalar D$_{s0}^*$(2317) and axial-vector D$_{s1}^*$(2460) charmed strange mesons are generated by coupled-channel dynamics through the s-wave scattering of Goldstone bosons off the pseudoscalar and vector D(D$_s$)-meson ground states. The attraction leading to the specific masses of these states reflects the chiral symmetry breaking scale which characterizes the Weinberg-Tomozawa interaction in the chiral Lagrangian. Chiral corrections to order Q$_\chi^2$ are calculated and found to be small. The D$_{s0}^*$(2317) and D$_{s1}^*$(2460) mesons decay either strongly into the isospin-violating $\pi^0$D$_s$ and $\pi^0$D$_s^*$ channels or electromagnetically. We show that the $\pi^0$-$\eta$ and (K$^0$D$^+$-K$^+$D$^0$) mixings act constructively to generate strong widths of the order of 140 keV. The one-loop contribution to the radiative decay amplitudes of scalar and axial-vector states is calculated using the electromagnetic Lagrangian to chiral order Q$_\chi^2$. We show the importance of taking into account processes involving light vector mesons explicitly in the dynamics of electromagnetic decays to obtain a satisfactory description of the available data.