We have studied the eta→pi+pi-e+e-(gamma) decay using about 1.7 fb−1 collected by the KLOE experiment at the DAFNE phi-factory. This corresponds to about 72 millions eta mesons produced in phi radiative decays. We have measured the branching ratio, inclusive of radiative effects, with 4% accuracy: BR(eta→ pi-pi-e+e-(gamma) = (26.8 ± 0.9Stat. ± 0.7Syst.) × 10^−5. We have obtained the first measurement of the CP-odd pipi-ee decay planes angular asymmetry, Aphi = (−0.6±2.5Stat. ±1.8Syst.)×10^−2.
Measurement of the branching ratio and search for a CP violating asymmetry in the eta ---> pi+ pi- e+ e-(gamma) decay at KLOE / Ambrosino, Fabio; Capussela, Tiziana; DI DONATO, Camilla; Massarotti, Paolo; Meola, Sabino; Napolitano, Marco; Perfetto, Francesco. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - STAMPA. - 675:(2009), pp. 283-288. [10.1016/j.physletb.2009.04.013]
Measurement of the branching ratio and search for a CP violating asymmetry in the eta ---> pi+ pi- e+ e-(gamma) decay at KLOE
AMBROSINO, FABIO;CAPUSSELA, TIZIANA;DI DONATO, CAMILLA;MASSAROTTI, PAOLO;MEOLA, SABINO;NAPOLITANO, MARCO;PERFETTO, FRANCESCO
2009
Abstract
We have studied the eta→pi+pi-e+e-(gamma) decay using about 1.7 fb−1 collected by the KLOE experiment at the DAFNE phi-factory. This corresponds to about 72 millions eta mesons produced in phi radiative decays. We have measured the branching ratio, inclusive of radiative effects, with 4% accuracy: BR(eta→ pi-pi-e+e-(gamma) = (26.8 ± 0.9Stat. ± 0.7Syst.) × 10^−5. We have obtained the first measurement of the CP-odd pipi-ee decay planes angular asymmetry, Aphi = (−0.6±2.5Stat. ±1.8Syst.)×10^−2.| File | Dimensione | Formato | |
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