Measurement of upper limits for the decay widths of D∗+ and D∗0

Abstract Upper limits for the decay widths of the D ∗+ and D ∗0 mesons have been measured using data from e + e − annihilations at √ s =29 GeV obtained with the High Resolution Spectrometer at PEP. We find Γ D ∗+ MeV /c 2 at 90% CL from an analysis of the mass difference distribution for the decay mode D ∗+ → D 0 π + . The D ∗+ − D 0 mass difference is also measured to be ((45.40±0.05±0.10) MeV/ c 2 . We determine Γ D ∗0 MeV /c 2 at 90% CL for a D ∗0 mass of 2007.2 MeV /c 2 , from a search for the decay mode D ∗0 → D + π − which could occur if the width were sufficiently large.