Journal article
Measurement of branching fractions, isospin, and CP-violating asymmetries for exclusive b→dγ modes
N Taniguchi, M Nakao, S Nishida, I Adachi, H Aihara, K Arinstein, T Aushev, T Aziz, AM Bakich, V Balagura, A Bay, K Belous, V Bhardwaj, U Bitenc, A Bondar, A Bozek, M Bračko, TE Browder, MC Chang, P Chang Show all
Physical Review Letters | Published : 2008
Abstract
We report new measurements of the decays B+→ρ+γ, B0→ρ0γ, and B0→ωγ using a data sample of 657×106 B meson pairs accumulated with the Belle detector at the KEKB e+e- collider. We measure branching fractions B(B+→ρ+γ)=(8.7-2.7-1. 1+2.9+0.9)×10-7, B(B0→ρ0γ)=(7.8-1.6-1.0+1.7+0.9)×10- 7, and B(B0→ωγ)=(4.0-1.7+1.9±1.3)×10-7. We also report the isospin asymmetry Δ(ργ)=-0.48-0.19-0.09+0.21+0.08 and the first measurement of the direct CP-violating asymmetry ACP(B+→ρ +γ)=-0.11±0.32±0.09, where the first and second errors are statistical and systematic, respectively. © 2008 The American Physical Society.
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 and JSPS (Japan); ARC and DEST (Australia); NSFC and KIP of CAS (China); DST (India); MOEHRD, KOSEF, and KRF (Korea); KBN (Poland); MES and RFAAE (Russia); ARRS (Slovenia); SNSF (Switzerland); NSC and MOE (Taiwan); and DOE (USA).