Decay of kaonium in a chiral approach

TL;DR

This paper non-perturbatively investigates the decay of kaonium using chiral perturbation theory, calculating its lifetime and energy shifts due to strong interactions with a regulated meson-meson scattering approach.

Contribution

It introduces a non-perturbative method to compute kaonium decay parameters using leading order chiral amplitudes and a specific cutoff in the meson-meson interaction model.

Findings

Kaonium lifetime estimated at approximately 2.2 x 10^-18 seconds.

Energy shifts and decay widths are computed for the 1s state.

A cutoff of about 1.4 GeV is used to regulate divergences.

Abstract

The decay of the K+K- hadronic atom kaonium is investigated non-perturbatively using meson-meson interaction amplitudes taken from leading order chiral perturbation theory in an approach adapted from that proposed by Oller and Oset [18]. The Kudryavtsev-Popov eigenvalue equation is solved numerically for the energy shift and decay width due to strong interactions in the 1s state. These calculations introduce a cutoff ~ 1.4 GeV in O(4) momentum space that is necessary to regulate divergent loop contributions to the meson-meson scattering amplitudes in the strong-interaction sector. One finds lifetimes of 2.2 \pm 0.9 x 10-18s for the ground state of kaonium.