We report a precise measurement of the masses of the Ξc (2645) and Ξc (2815) baryons using a data sample of 414 fb-1 collected by the Belle Collaboration at the KEKB e+ e- collider. The states Ξc (2645)0, + are observed in the Ξc+, 0 π-, + decay modes, while the Ξc (2815)0, + are reconstructed in the Ξc (2645)+, 0 π-, + decay modes. The following mass splittings are determined: mΞc (2645)+ - mΞc (2645)0 = (- 0.1 ± 0.3 (stat) ± 0.6 (syst)) MeV / c2 and mΞc (2815)+ - mΞc (2815)0 = (- 3.4 ± 1.9 (stat) ± 0.9 (syst)) MeV / c2 with a much better precision than the current world averages. We also observe a new decay mode, Ξc (2980)0, + → Ξc (2645)+, 0 π-, +.
|Number of pages||7|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - 2008 Jul 3|
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 Super-SINET network support. We acknowledge support from the Ministry of Education, Culture, Sports, Science, and Technology of Japan and the Japan Society for the Promotion of Science; the Australian Research Council and the Australian Department of Education, Science and Training; the National Natural Science Foundation of China under contract Nos. 10575109 and 10775142; 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. R01-2005-000-10089-0) of the Korea Science and Engineering Foundation, and the Pure Basic Research Group program of the Korea Research Foundation; the Polish State Committee for Scientific Research; 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.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics