First observation of the Cabibbo-suppressed decays Ξc+→Σ+π−π+ and Ξc+→Σ−π+π+ and measurement of their branching ratios

Autor: P. Mathew, I. Eschrich, P. S. Cooper, C. R. Newsom, Vincent J Smith, A.G. Dolgolenko, K. D. Nelson, A. Lamberto, Nikolay Terentyev, M. Mattson, G. F. Rappazzo, I. Giller, D. V. Vavilov, I. Konorov, T. Lungov, S. Y. Jun, E. Vázquez-Jáuregui, J. Kilmer, M. Procario, Victor Kim, Lev Uvarov, A. P. Nilov, G.V. Davidenko, J. Amaro-Reyes, P. Gouffon, M. A. Kubantsev, M. Gaspero, G. B. Dzyubenko, R. M. Edelstein, A. Blanco-Covarrubias, R. Zukanovich-Funchal, Ugur Akgun, Mithat Kaya, E. J. Ramberg, M. Srivastava, Chensheng Mao, Wenheng Zhao, J. Simon, James Russ, H. Krü, Erhan Gülmez, E. McCliment, I. Torres, E. M. Leikin, V. P. Maleev, J. M. You, V. A. Prutskoi, Victor Golovtsov, Zhenlin Mao, A. I. Kulyavtsev, A.V. Nemitkin, P. Schiavon, V. I. Rud, C.O. Escobar, B. V. Razmyslovich, N. Estrada, A. Morelos, L. M. Kochenda, F. G. Garcia, S. B. Nurushev, G. Alkhazov, Shuchen Zheng, L. Stutte, J.L. Sánchez-López, V. S. Verebryusov, V. V. Molchanov, A. G. Krivshich, Murray Moinester, L. J. Dauwe, M. Luksys, L.G. Landsberg, D. Skow, V. P. Kubarovsky, Aldo Penzo, Suat Ozkorucuklu, U. Dersch, I. Larin, A. Kushnirenko, Jürgen Engelfried, N. P. Kuropatkin, Yasar Onel, A. P. Kozhevnikov, Andrey Vasiliev, A. I. Sitnikov, M. Svoiski, V. A. Victorov, J. Lach, K. Vorwalter, A. A. Vorobyov, Kangling He, V. Stepanov, V. F. Kurshetsov, S. V. Petrenko, I.S. Filimonov, A. V. Evdokimov, Viktor Matveev, M. Iori, Nikolay Bondar, G. P. Thomas, P. Pogodin, L. Emediato, A. Ocherashvili, V. E. Vishnyakov, A.G. Atamantchouk, Ahmet S. Ayan, P. V. Neoustroev, E. Ozel, Yunshan Li, D. Mao, G. Ló, V. Steiner, Simon Kwan, M.Y. Balatz, A. M. F. Endler
Rok vydání: 2008
Předmět:
Zdroj: Physics Letters B. 666:299-304
ISSN: 0370-2693
DOI: 10.1016/j.physletb.2008.07.072
Popis: We report the first observation of two Cabibbo-suppressed decay modes, Ξ c + → Σ + π − π + and Ξ c + → Σ − π + π + . We observe 59 ± 14 over a background of 87, and 22 ± 8 over a background of 13 events, respectively, for the signals. The data were accumulated using the SELEX spectrometer during the 1996–1997 fixed target run at Fermilab, chiefly from a 600 GeV / c Σ − beam. The branching ratios of the decays relative to the Cabibbo-favored Ξ c + → Ξ − π + π + are measured to be B ( Ξ c + → Σ + π − π + ) / B ( Ξ c + → Ξ − π + π + ) = 0.48 ± 0.20 , and B ( Ξ c + → Σ − π + π + ) / B ( Ξ c + → Ξ − π + π + ) = 0.18 ± 0.09 , respectively. We also report branching ratios for the same decay modes of the Λ c + relative to Λ c + → p K − π + .
Databáze: OpenAIRE
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