Journal article

Evidence for B -> K eta 'gamma decays at Belle

R Wedd, I Adachi, H Aihara, K Arinstein, V Aulchenko, AM Bakich, V Balagura, E Barberio, A Bay, K Belous, V Bhardwaj, M Bischofberger, A Bondar, A Bozek, M Bracko, TE Browder, Y Chao, A Chen, BG Cheon, I-S Cho Show all

PHYSICAL REVIEW D | AMER PHYSICAL SOC | Published : 2010

Abstract

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. ©..

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Grants

Funding Acknowledgements

We thank the KEKB group for excellent operation of the accelerator, the KEK cryogenics group for efficient solenoid operations, and the KEK computer group and the NII for valuable computing and SINET3 network support. We acknowledge support from MEXT, JSPS, and Nagoya's TLPRC (Japan); ARC and DIISR (Australia); NSFC (China); DST (India); MOEHRD and KOSEF (Korea); MNiSW (Poland); MES and RFAAE (Russia); ARRS (Slovenia); SNSF (Switzerland); NSC and MOE (Taiwan); and the DOE (USA).