Journal article

Measurement of the (B)over-bar -> X-s gamma branching fraction with a sum of exclusive decays

T Saito, A Ishikawa, H Yamamoto, A Abdesselam, I Adachi, H Aihara, S Al Said, K Arinstein, DM Asner, T Aushev, R Ayad, AM Bakich, V Bansal, B Bhuyan, A Bobrov, A Bondar, G Bonvicini, A Bozek, M Bracko, TE Browder Show all



We use 772×106 BB¯ meson pairs collected at the ?(4S) resonance with the Belle detector to measure the branching fraction for B¯→Xsγ. Our measurement uses a sum-of-exclusives approach in which 38 of the hadronic final states with strangeness equal to +1, denoted by Xs, are reconstructed. The inclusive branching fraction for MXs<2.8GeV/c2, which corresponds to a minimum photon energy of 1.9 GeV, is measured to be B(B¯→Xsγ)=(3.51±0.17±0.33)×10-4, where the first uncertainty is statistical and the second is systematic.


Awarded by Austrian Science Fund

Awarded by National Natural Science Foundation of China

Awarded by Ministry of Education, Youth and Sports of the Czech Republic

Awarded by Istituto Nazionale di Fisica Nucleare of Italy; the National Research Foundation of Korea

Awarded by BRL program under NRF Grants

Awarded by Center for Korean J-PARC Users

Awarded by UPV/EHU under program

Awarded by Grants-in-Aid for Scientific Research

Funding Acknowledgements

We thank the KEKB group for the excellent operation of the accelerator; the KEK cryogenics group for the efficient operation of the solenoid; and the KEK computer group, the National Institute of Informatics, and the PNNL/EMSL computing group for valuable computing and SINET4 network support. We acknowledge support from the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japan, the Japan Society for the Promotion of Science (JSPS), and the Tau-Lepton Physics Research Center of Nagoya University; the Australian Research Council; Austrian Science Fund under Grants No. P 22742-N16 and No. P 26794-N20; the National Natural Science Foundation of China under Contracts No. 10575109, No. 10775142, No. 10825524, No. 10875115, No. 10935008 and No. 11175187; the Ministry of Education, Youth and Sports of the Czech Republic under Contract No. LG14034; the Carl Zeiss Foundation, the Deutsche Forschungsgemeinschaft and the VolkswagenStiftung; the Department of Science and Technology of India; the Istituto Nazionale di Fisica Nucleare of Italy; the National Research Foundation of Korea Grants No. 2011-0029457, No. 2012-0008143, No. 2012R1A1A2008330, No. 2013R1A1A3007772, No. 2014R1A2A2A01005286, No. 2014R1A2A2A01002734, No. 2014R1A1A2006456; the BRL program under NRF Grants No. KRF-20110020333, No. KRF-2011-0021196, Center for Korean J-PARC Users, No. NRF-2013K1A3A7A06056592; the BK21 Plus program and the GSDC of the Korea Institute of Science and Technology Information; the Polish Ministry of Science and Higher Education and the National Science Center; the Ministry of Education and Science of the Russian Federation and the Russian Federal Agency for Atomic Energy; the Slovenian Research Agency; the Basque Foundation for Science (IKERBASQUE) and the UPV/EHU under program UFI 11/55; the Swiss National Science Foundation; the National Science Council and the Ministry of Education of Taiwan; and the U.S. Department of Energy and the National Science Foundation. This work is supported by a Grant-in-Aid from MEXT for Science Research in a Priority Area ("New Development of Flavor Physics") and from JSPS for Creative Scientific Research ("Evolution of Tau-lepton Physics").