Observation of the Radiative Decay $D^{*+}\to D^{+}\gamma$

Abstract

We have observed a signal for the decay D*+ -> D+ gamma at a significance of 4 standard deviations. From the measured branching ratio B(D*+ -> D+ gamma)/B(D*+ -> D+ pi0)=0.055 +- 0.014 +- 0.010 we find B(D*+ -> D+ gamma)= 0.017 +- 0.004 +- 0.003, where the first uncertainty is statistical and the second is systematic. We also report the highest precision measurements of the remaining D*+ branching fractions.