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 Cornell Electron-positron Storage Ring beam spot to measure the energy release distribution from the D*+ → D0π+ decay. We find Γ(D*+) = 96 ±4(stat) ± 22(syst)keV. We also measure the energy release in the decay and compute Δm = mD*+ − mD0 = 145.412 ± 0.002(stat) ± 0.012(syst)MeV/c2.
ASJC Scopus subject areas
- Physics and Astronomy(all)