We report the results of a study of B ±→K ±η c and B ±→K ±η c(2S) decays followed by η c and η c(2S) decays to (K SKπ) 0. The results are obtained from a data sample containing 535 million BB --meson pairs collected by the Belle experiment at the KEKB e +e - collider. We measure the products of the branching fractions B(B±→K±ηc)B(ηc→KSK±π∓)=(26.7±1.4(stat)-2.6+2.9(syst)±4.9(model))×10-6 and B(B±→K±ηc(2S))B(ηc(2S)→KSK±π∓)=(3.4-1.5+2.2(stat+model)-0.4+0.5(syst))×10-6. Interference with the non-resonant component leads to significant model uncertainty in the measurement of these product branching fractions. Our analysis accounts for this interference and allows the model uncertainty to be reduced. We also obtain the following charmonia masses and widths: M(ηc)=(2985.4±1.5(stat)-2.0+0.5(syst)) MeV/c2, Γ(ηc)=(35.1±3.1(stat)-1.6+1.0(syst)) MeV/c2, M(ηc(2S))=(3636.1-4.2+3.9(stat+model)-2.0+0.7(syst)) MeV/c2, Γ(ηc(2S))=(6.6-5.1+8.4(stat+model)-0.9+2.6(syst)) MeV/c2.
|Number of pages||11|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - 2011 Dec 6|
Bibliographical noteFunding Information:
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 Nos. 10575109 , 10775142 , 10875115 and 10825524 ; the Ministry of Education, Youth and Sports of the Czech Republic under contract Nos. LA10033 and MSM0021620859 ; the Department of Science and Technology of India ; the BK21 and WCU program of the Ministry Education Science and Technology, National Research Foundation of Korea , and NSDC of the Korea Institute of Science and Technology Information ; 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 US 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”).
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics