Dalitz plot distributions in presence of triangle singularities

TL;DR

This paper investigates how triangle singularities affect three-particle Dalitz plot distributions in coupled channels, revealing that such singularities can be visible in individual channel projections but not in the summed intensities.

Contribution

It extends previous single-channel analyses to coupled channels, showing that triangle singularities can be observed in individual channel projections.

Findings

Triangle singularities are visible in individual channel Dalitz plot projections.

In coupled channels, the sum of all channel intensities masks the singularities.

The results clarify how unitarity influences observable effects of singularities.

Abstract

We discuss properties of three-particle Dalitz distributions in coupled channel systems in presence of triangle singularities. The single channel case was discussed long ago where it was found that as a consequence of unitarity, effects of a triangle singularity seen in the Dalitz plot are not seen in Dalitz plot projections. In the coupled channel case we find the same is true for the sum of intensities of all interacting channels. Unlike the single channel case, however, triangle singularities do remain visible in Dalitz plot projections of individual channels.