ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2010, vol. 81, p. -
Evidence for B→Kη′γ decays at Belle
We present the results of a search for the radiative decay B→Kη′γ and find evidence for B +→K+η′γ decays at the 3.3 standard deviation level with a partial branching fraction of (3.6±1.2±0.4)×10-6, where the first error is statistical and the second systematic. This measurement is restricted to the region of combined Kη′ invariant mass less than 3.4GeV/c2. A 90% confidence level upper limit of 6.4×10-6 is obtained for the partial branching fraction of the decay B0→K0η ′γ in the same Kη′ invariant mass region. These results are obtained from a 605fb-1 data sample containing 657×106BB̄ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. © 2010 The American Physical Society.