Light meson and baryon spectroscopy from charm decays in Fermilab E791

TL;DR

This paper reports on resonance analysis in charm decays from Fermilab E791, revealing polarization effects and scalar resonances in $ ext{D}^+$ and $ ext{D}_s^+$ decays, advancing understanding of light meson and baryon spectroscopy.

Contribution

It provides the first detailed resonant analysis of charm decays, including polarization measurements and evidence for scalar resonances, using a comprehensive 5-dimensional approach.

Findings

Significant polarization of $ ext{Lambda}_c^+$ observed.

Evidence for a broad scalar resonance in $ ext{D}^+$ decays.

Insignificant asymmetry in $f_0(980)$ Breit Wigner description.

Abstract

We present results from Fermilab experiment E791. We extracted the fractions of resonant components in the $\Lambda_c^+\to p K^- \pi^+$ decays, and found a significant polarization of the $\Lambda_c^+$ using a fully 5-dimensional resonant analysis. We also did resonant analyses of $D^+$ and $D^+_s$ decays into $\pi^+\pi^-\pi^+$. We observed an insignificant asymmetry in the Breit Wigner describing the $f_0(980)$ and found good evidence for a light and broad scalar resonance in the $D^+$ decays.