We present the first measurement of the D*+ width using 9/fb of e+e- data collected near the γ(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 *+ → D0π++ decay. We find Γ(D*+) = 96±4 (statistical)±22 (systematic) keV. We also measure the energy release in the decay and compute Δm≡mD*+ +-mD0= 145.412±0.002 (statistical) ±0.012 (systematic) MeV/c2.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)