Measurement of Charm Meson Lifetimes

TL;DR

This paper reports precise measurements of the lifetimes of charm mesons D^0, D^+, and D_s^+ using e+e- collision data, revealing significant differences in their decay durations and providing insights into charm quark behavior.

Contribution

First measurement of charm meson lifetimes with comparable precision to previous results, highlighting a significant lifetime ratio difference between D_s^+ and D^0.

Findings

D^0 lifetime: 408.5 fs

D^+ lifetime: 1033.6 fs

D_s^+ lifetime: 486.3 fs

Abstract

We report measurements of the $D^0, D^+$, and $D^+_s$ meson lifetimes using $3.7 fb^{-1}$ of e^+e^- annihilation data collected near the $\Upsilon(4S)$ resonance with the CLEO detector. The lifetimes of the $D^0, D^+$, and $D^+_s$ mesons are measured to be $408.5 \pm 4.1 ^{+3.5}_{-3.4} fs, 1033.6 \pm 22.1 ^{+9.9}_{-12.7} fs$, and $486.3 \pm 15.0 ^{+4.9}_{-5.1} fs$, respectively. The precisions of the charm meson lifetimes reported here are comparable to those of the best previous measurements, and the systematic errors are very different. In a single experiment we find that the ratio of the $D^+_s$ and $D^0$ lifetimes differs from one by more than 4.5 standard deviations.