Journal article
Observation of B →pΛ̄γ
YJ Lee, MZ Wang, K Abe, K Abe, H Aihara, Y Asano, V Aulchenko, T Aushev, S Bahinipati, AM Bakich, I Bedny, U Bitenc, I Bizjak, A Bondar, A Bozek, M Bračko, J Brodzicka, TE Browder, MC Chang, P Chang Show all
Physical Review Letters | AMER PHYSICAL SOC | Published : 2005
Abstract
We report the first observation of the radiative hyperonic B decay B+→pΛ̄γ, using a 140fb-1 data sample recorded on the Υ(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e- collider. The measured branching fraction is B(B+→pΛ̄γ)= (2.16-0.53+0.58±0.20)×10-6. We examine its MpΛ̄ distribution and observe a peak near threshold. This feature is expected by the short-distance b→sγ transition. A search for B+→pΣ̄ 0γ yields no significant signal, and we set a 90% confidence-level upper limit on the branching fraction of B(B+→pΣ̄0γ)<4. 6×10-6. © 2005 The American Physical Society.