Journal article

Measurement of the branching fraction for the decay Gamma(4S) -> Gamma(1S)pi( ) pi(-)

A Sokolov, M Shapkin, H Aihara, K Arinstein, T Aushev, AM Bakich, E Barberio, A Bay, K Belous, V Bhardwaj, A Bondar, M Bracko, TE Browder, M-C Chang, P Chang, A Chen, K-F Chen, BG Cheon, C-C Chiang, R Chistov Show all



We study transitions between Υ states with the emission of charged pions using 604.6fb-1 of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The measured product branching fraction is B(Υ(4S)→Υ(1S)π+π-)×B(Υ(1S)→μ+μ-)=(2. 11±0.30(stat)±0.14(sys))×10-6 and the partial decay width is Γ(Υ(4S)→Υ(1S)π+π-)=(1.75±0.25(stat)±0. 24(sys))keV. © 2009 The American Physical Society.


Awarded by National Natural Science Foundation of China

Awarded by CHEP SRC program and Basic Research program

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 and the National Institute of Informatics for valuable computing and SINET3 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 and the Australian Department of Industry, Innovation, Science and Research; the National Natural Science Foundation of China under Contract No. 10575109, No. 10775142, No. 10875115, and No. 10825524; the Department of Science and Technology of India; the BK21 program of the Ministry of Education of Korea, the CHEP SRC program and Basic Research program (Grant No. R01-2008-000-10477-0) of the Korea Science and Engineering Foundation; the Polish Ministry of Science and Higher Education; the Ministry of Education and Science of the Russian Federation and the Russian Federal Agency for Atomic Energy; the Slovenian Research Agency; the Swiss National Science Foundation; the National Science Council and the Ministry of Education of Taiwan; and the U.S. Department of Energy. 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'').