Measurement of the branching fractions of the radiative charm decays D0→¯¯¯¯K*0γ and D0→ϕγ

Abstract

We present a measurement of the branching fractions for the Cabibbo-favored radiative decay D 0 → ¯¯¯¯ K * 0 γ and the Cabibbo-suppressed radiative decay D 0 → ϕ γ . These measurements are based on a data sample corresponding to an integrated luminosity of 387.1 fb − 1 and recorded with the BABAR detector at the PEP-II e + e − asymmetric-energy collider operating at center-of-mass energies 10.58 and 10.54 GeV. We measure the branching fractions relative to the well-studied decay D 0 → K − π + and find B ( D 0 → ¯¯¯¯ K * 0 γ ) / B ( D 0 → K − π + ) = ( 8.43 ± 0.51 ± 0.70 ) × 10 − 3 and B ( D 0 → ϕ γ ) / B ( D 0 → K − π + ) = ( 7.15 ± 0.78 ± 0.69 ) × 10 − 4 , where the first error is statistical and the second is systematic. This is the first observation of the decay mode D 0 → ¯¯¯¯ K * 0 γ .