Charm lifetime measurements at Belle II

TL;DR

This paper presents high-precision lifetime measurements of various charmed mesons and baryons at Belle II, providing the most accurate values to date and confirming the relative lifetimes of certain particles.

Contribution

First precise measurements of multiple charmed hadron lifetimes at Belle II, improving accuracy and confirming theoretical lifetime hierarchies.

Findings

Most precise measurements for $ au(D_s^+)$, $ au(D^+)$, $ au(D^0)$, and $ au(\Lambda_c^+)$

Confirmed that $ au(\Omega_c^0)$ exceeds $ au(\Lambda_c^+)$ and $ au(\Xi_c^0)$

Results enhance understanding of charm hadron decay dynamics

Abstract

We report precision measurements of lifetimes of charmed mesons and baryons performed by the Belle II experiment. Specifically, we measure $D_s^+$, $D^+$, $D^0$, $\Lambda_c^+$, and $\Omega_c^0$ lifetimes. Our results for $\tau(D_s^+)$, $\tau(D^+)$, $\tau(D^0)$, and $\tau(\Lambda_c^+)$ are the world's most precise; our result for $\tau(\Omega_c^0)$ confirms that the $\Omega_c^0$ lifetime is longer than that of the $\Lambda_c^+$ and the $\Xi_c^0$.