학술논문
A study of the radiative K.sub.L[right arrow][p[i].sup.+-[]e.sup.a]I1/2I3 decay and search for direct photon emission with the KLOE detector
Document Type
Report
Author
Ambrosino, F.; Antonelli, A.; Antonelli, M.; Archilli, F.; Bacci, C.; Beltrame, P.; Bencivenni, G.; Bertolucci, S.; Bini, C.; Bloise, C.; Bocchetta, S.; Bossi, F.; Branchini, P.; Caloi, R.; Campana, P.; Capon, G.; Capussela, T.; Ceradini, F.; Cesario, F.; Chi, S.; Chiefari, G.; 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, B.; Doria, A.; Dreucci, M.; Felici, G.; Ferrari, A.; Ferrer, M.L.; Fiore, S.; Forti, C.; Franzini, P.; Gatti, C.; Gauzzi, P.; Giovannella, S.; Gorini, E.; Graziani, E.; Kluge, W.; Kulikov, V.; Lacava, F.; Lanfranchi, G.; Lee-Franzini, J.; Leone, D.; Martini, M.; Massarotti, P.; Mei, W.; Meola, S.; Miscetti, S.; Moulson, M.; Muller, S.; Murtas, F.; Napolitano, M.; Nguyen, F.; Palutan, M.; Pasqualucci, E.; Passeri, A.; Patera, V.; Perfetto, F.; Primavera, M.; Santangelo, P.; Saracino, G.; Sciascia, B.; Sciubba, A.; Sibidanov, A.; Spadaro, T.; Testa, M.; Tortora, L.; Valente, P.; Venanzoni, G.; Versaci, R.; Xu, G.
Source
The European Physical Journal C - Particles and Fields. June, 2008, Vol. 55 Issue 4, p539, 8 p.
Subject
Language
English
ISSN
1434-6044
Abstract
We present a measurement of the ratio R=I(K.sup.0 .sub.e3I3 E.sup.* .sub.I3 > 30 MeV, I,.sup.* .sub.I3>20.sup.deg)/I(K.sup.0 .sub.e3) and a first measurement of the direct emission contribution in semileptonic K.sub.L decays. The measurement was performed at the DA NE I factory by selecting I[right arrow][K.sub.L]K.sub.S decays with the KLOE detector. We use 328 pb.sup.-1 of data, corresponding to about 3.5 million K.sup.0 .sub.e3 events and about 9000 K.sup.0 .sub.e3I3 radiative events. Our result is R=(924+-23.sub.stat+-16.sub.syst)x10.sup.-5 for the branching ratio and a(c)Xaa=-2.3+-1.3.sub.stat+-1.4.sub.syst for the effective strength parameter describing direct emission.