The phi to pi+ pi- decay within a chiral unitary approach

TL;DR

This paper models the phi to pi+ pi- decay using a chiral unitary approach, highlighting the roles of meson-meson interactions, mixing effects, and interference patterns to interpret experimental data.

Contribution

It introduces a non-perturbative chiral unitary framework for meson interactions, analyzing phi decay mechanisms and mixing effects with improved theoretical detail.

Findings

Kaon-loop contribution to phi-rho mixing quantified.

Interference effects significantly influence decay amplitude.

Potential to distinguish phi-omega mixing scenarios experimentally.

Abstract

Starting from the Chiral Perturbation Theory Lagrangian, but keeping different masses for the charged and neutral mesons, and using a previously developed non-perturbative unitary scheme that generates the lightest meson-meson resonances, we construct K Kbar to K Kbar and K Kbar to pi+ pi- in the vector channel. This allows us to obtain the kaon-loop contribution to the phi-rho mixing and study the phi to pi+pi- decay. The dominant contribution to this decay comes from the phi to gamma to pi+pi- process. However, there can be large interferences with the subdominant contributions coming from phi-rho and phi-omega mixing, or of these two contributions among themselves. As a consequence, a reliable measurement of phi to pi+pi- decay could be used to differentiate between some phi-omega mixing scenarios proposed in the literature.