학술논문
Upper limit on the eta -> pi(+)pi(-) branching fraction with the KLOE experiment
Document Type
Author
Babusci, D.; Berlowski, M.; Bloise, C.; Bossi, F.; Branchini, P.; Budano, A.; Cao, Bo; Ceradini, F.; Ciambrone, P.; Curciarello, F.; Czerwinski, E.; D'Agostini, G.; Dane, E.; De Leo, V.; De Lucia, E.; De Santis, A.; De Simone, P.; Di Cicco, A.; Di Domenico, A.; Domenici, D.; D'Uffizi, A.; Fantini, A.; Fermani, P.; Fiore, S.; Gajos, A.; Gauzzi, P.; Giovannella, S.; Graziani, E.; Ivanov, V. L.; Johansson, Tord; Kang, X.; Kisielewska-Kaminska, D.; Kozyrev, E. A.; Krzemien, W.; Kupsc, Andrzej; Lukin, P. A.; Mandaglio, G.; Martini, M.; Messi, R.; Miscetti, S.; Moricciani, D.; Moskal, P.; Parzych, S.; Passeri, A.; Patera, V.; del Rio, E. Perez; Santangelo, P.; Schioppa, M.; Selce, A.; Silarski, M.; Sirghi, F.; Solodov, E. P.; Tortora, L.; Venanzoni, G.; Wislicki, W.; Wolke, Magnus
Source
Journal of High Energy Physics (JHEP). (10)
Subject
Language
English
ISSN
1126-6708
1029-8479
1029-8479
Abstract
Based on an integrated luminosity of 1.61 fb(-1)e(+)e(-) collision data collected with the KLOE detector at DA Phi NE, the Frascati phi -factory, a search for the P- and CP-violating decay eta -> pi (+)pi (-) has been performed. Radiative phi -> eta gamma decay is exploited to access the eta mesons. No signal is observed in the pi (+)pi (-) invariant mass spectrum, and the upper limit on the branching fraction at 90% confidence level is determined to be B(eta -> pi (+)pi (-)) < 4.9 x 10(-6), which is approximately three times smaller than the previous KLOE result. From the combination of these two measurements we get B( -> pi (+)pi (-)) < 4.4 x 10(-6) at 90% confidence level.