Title: | Measurement of the branching ratio and search for a CP violating asymmetry in the η→π+π−e+e− (γ ) decay at KLOE |
Authors: | Ambrosino, F. Antonelli, A. Antonelli, M. Archilli, F. Beltrame, P. Bencivenni, G. Bertolucci, S. Bini, C. Bloise, C. Bocchetta, Simona Bossi, F. Branchini, Paolo Capon, G. Capussela, T. Ceradini, Filippo Ciambrone, P. Crucianelli, F. De Lucia, E. De Santis, A. De Simone, P. De Zorzi, G. Denig, A. Di Domenico, A. Di Donato, C. Di Micco, Biagio Dreucci, M. Felici, G. Fiore, S. Franzini, P. Gatti, C. Gauzzi, P. Giovannella, S. Graziani, Enrico Lanfranchi, G. Lee-Franzini, J. Leone, D. Martini, M. Massarotti, P. Meola, S. Miscetti, S. Moulson, M. Mueller, S. Murtas, F. Napolitano, M. Nguyen, Federico Palutan, M. Pasqualucci, E. Passeri, Antonio Patera, V. Perfetto, F. Santangelo, P. Sciascia, B. Spadaro, T. Testa, M. Tortora, Ludovico Valente, P. Venanzoni, G. Versaci, R. Xu, G. |
Keywords: | MONTE-CARLO ETA-& gt PI(+)PI(-)E(+)E(-) DETECTOR PHOTOS |
Issue Date: | 18-May-2009 |
Publisher: | Elsevier |
Abstract: | We have studied the η→π+π−e+e− (γ ) decay using about 1.7 fb−1 collected by the KLOE experiment at the DA NE φ-factory. This corresponds to about 72 millions η mesons produced in φ radiative decays. We have measured the branching ratio, inclusive of radiative effects, with 4% accuracy: BR(η→
π+π−e+e− (γ )) = (26.8 ± 0.9Stat. ± 0.7Syst.) × 10−5. We have obtained the first measurement of the CPodd ππ–ee decay planes angular asymmetry, Aφ = (−0.6±2.5Stat. ±1.8Syst.)×10−2. |
URI: | http://hdl.handle.net/2307/358 |
ISSN: | 0370-2693 |
DOI: | 10.1016/j.physletb.2009.04.013 |
Appears in Collections: | A - Articolo su rivista X_Dipartimento di Fisica 'Edoardo Amaldi'
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