Light Meson Physics from Charm Decays at Fermilab E791

TL;DR

This paper reports on Dalitz plot analyses of charm decays from Fermilab E791, revealing significant contributions of scalar mesons like $$ and $$, and providing evidence for the $$ and $$ mesons, highlighting charm decays as a new avenue for light meson research.

Contribution

It presents the first evidence for the light and broad $$ meson and measures its properties, demonstrating charm decays as a new environment for light meson studies.

Findings

Evidence for the $$ meson with measured mass and width

Observation of the $$ meson in charm decays

Measurement of $f_0$ parameters and $$ meson evidence

Abstract

We present recent results on light mesons based on Dalitz plot analyses of charm decays from Fermilab experiment E791. Scalar mesons are found to have large contributions to the decays studied, $D^+\to K^-\pi^+\pi^+$ and $D^+, D_s^+\to\pi^-\pi^+\pi^+$. From the $K\pi\pi$ final state, we find good evidence for the existence of the light and broad $\kappa$ meson and we measure its mass and width. We also discuss recently published results on the 3$\pi$ final states, especially the measurement of the $f_0$ parameters and the evidence for the $\sigma$ meson from $D^+\to\sigma\pi^+$. These results demonstrate the importance of charm decays as a new environment for the study of light meson physics.