Measurement of the branching ratio and search for a CP violating asymmetry in the η→π+π−e+e− (γ ) decay at KLOE

2011-12-22T13:34:34Z

Measurement of the branching ratio and search for a CP violating asymmetry in the η→π+π−e+e− (γ ) decay at KLOE 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. 2009-05-18 Physics Letters B 675 283-288 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.

A global fit to determine the pseudoscalar mixing angle and the gluonium content of the eta ' meson

2011-12-22T13:35:28Z

A global fit to determine the pseudoscalar mixing angle and the gluonium content of the eta ' meson 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.; 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; Jacewicz, M.; Lanfranchi, G.; Lee-Franzini, J.; 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.; Santangelo, P.; Sciascia, B.; Spadaro, T.; Testa, M.; Tortora, Ludovico; Valente, P.; Venanzoni, G.; Versaci, R.; Xu, G. 2009-07-31 Journal of High Energy Physics 7 105 We update the values of the eta-eta' mixing angle and of the eta' gluonium content by fitting our measurement R-phi = BR(phi -> etagamma)/BR(phi -> eta gamma) together with several vector meson radiative decays to pseudoscalars (V -> P gamma), pseudoscalar mesons radiative decays to vectors (P -> V gamma) and the eta' -> gamma gamma,pi(0) -> gamma gamma widths. From the fit we extract a gluonium fraction of Z(G)(2) = 0.12 +/- 0.04, the pseudoscalar mixing angle psi(P) = (40.4 +/- 0.6) degrees and the phi - omega mixing angle psi(V)= (3.32 +/- 0.09)degrees. Z(G)(2) and psi(P) are fairly consistent with those previously published. We also evaluate the impact on the eta' gluonium content determination of future experimental improvements of the eta' branching ratios and decay width.

ArcAdiA

Measurement of the branching ratio and search for a CP violating asymmetry in the η→π+π−e+e− (γ ) decay at KLOE

A global fit to determine the pseudoscalar mixing angle and the gluonium content of the eta ' meson