The ratio of branching fractions of the radiative B decays B 0→K *0γ and Bs0→φγ has been measured using an integrated luminosity of 1.0 fb -1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s=7 TeV. The value obtained isB(B0→K*0γ)B(Bs0→φγ)=1.23±0.06 (stat.)±0.04 (syst.)±0.10(fs/fd), where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions f s/f d. Using the world average value for B(B0→K*0γ), the branching fraction B(Bs0→φγ) is measured to be (3.5±0.4)×10 -5.The direct CP asymmetry in B 0→K *0γ decays has also been measured with the same data and found to beACP(B0→K*0γ)=(0.8±1.7 (stat.)±0.9 (syst.))%.Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations.
Bibliographical noteFunding Information:
We express our gratitude to our colleagues in the CERN accelerator departments for the excellent performance of the LHC. We thank the technical and administrative staff at CERN and at the LHCb institutes, and acknowledge support from the National Agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil) ; CERN; NSFC (China) ; CNRS/IN2P3 (France) ; BMBF, DFG, HGF and MPG (Germany) ; SFI (Ireland) ; INFN (Italy) ; FOM and NWO (The Netherlands) ; SCSR (Poland) ; ANCS (Romania) ; MinES of Russia and Rosatom (Russia) ; MICINN, XuntaGal and GENCAT (Spain) ; SNSF and SER (Switzerland) ; NAS Ukraine (Ukraine) ; STFC (United Kingdom) ; NSF (USA) . We also acknowledge the support received from the ERC under FP7 and the Region Auvergne.
Copyright 2012 Elsevier B.V., All rights reserved.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics