First Measurement of Gamma(D*+) and Precision Measurement of m_D*+ - m_D0

TL;DR

This paper reports the first measurement of the D*+ meson width and a precise determination of the mass difference between D*+ and D0 using data from the CLEO II.V detector, employing advanced tracking and reconstruction techniques.

Contribution

It provides the first measurement of the D*+ width and a highly precise value of the mass difference, improving understanding of charm meson properties.

Findings

Gamma(D*+) = 96 +- 4 (stat) +- 22 (sys) keV

Delta m = 145.412 +- 0.002 (stat) +- 0.012 (sys) MeV/c^2

First measurement of D*+ width and precise mass difference

Abstract

We present the first measurement of the D*+ width using 9/fb of e+ e- data collected near the Upsilon(4S) resonance by the CLEO II.V detector. Our method uses advanced tracking techniques and a reconstruction method that takes advantage of the small vertical size of the CESR beam spot to measure the energy release distribution from the D*+ -> D0 pi+ decay. We find Gamma(D*+) = 96 +- 4 (Statistical) +- 22 (Systematic) keV. We also measure the energy release in the decay and compute Delta m = m(D*+) - m(D0) = 145.412 +- 0.002 (Statistical) +- 0.012 (Systematic) MeV/c^2