Upper limit on the η→γγγ branching ratio with the KLOE detector

• Published in: Physics letters. B 2004-07, Vol.591 (1-2), p.49-54
• Main Authors: Aloisio, A, Ambrosino, F, Antonelli, A, Antonelli, M, Bacci, C, Bencivenni, G, Bertolucci, S, Bini, C, Bloise, C, Bocci, V, Bossi, F, Branchini, P, Bulychjov, S.A, Caloi, R, Campana, P, Capon, G, Capussela, T, Carboni, G, Ceradini, F, Cervelli, F, Cevenini, F, Chiefari, G, Ciambrone, P, Conetti, S, De Lucia, E, De Simone, P, De Zorzi, G, Dell'Agnello, S, Denig, A, Di Domenico, A, Di Donato, C, Di Falco, S, Di Micco, B, Doria, A, Dreucci, M, Erriquez, O, Farilla, A, Felici, G, Ferrari, A, Ferrer, M.L, Finocchiaro, G, Forti, C, Franzini, P, Gatti, C, Gauzzi, P, Giovannella, S, Gorini, E, Graziani, E, Incagli, M, Kluge, W, Kulikov, V, Lacava, F, Lanfranchi, G, Lee-Franzini, J, Leone, D, Lu, F, Martemianov, M, Matsyuk, M, Mei, W, Merola, L, Messi, R, Miscetti, S, Moulson, M, Müller, S, Murtas, F, Napolitano, M, Nguyen, F, Palutan, M, Pasqualucci, E, Passalacqua, L, Passeri, A, Patera, V, Perfetto, F, Petrolo, E, Pontecorvo, L, Primavera, M, Santangelo, P, Santovetti, E, Saracino, G, Schamberger, R.D, Sciascia, B, Sciubba, A, Scuri, F, Sfiligoi, I, Sibidanov, A, Spadaro, T, Spiriti, E, Testa, M, Tortora, L, Valente, P, Valeriani, B, Venanzoni, G, Veneziano, S, Ventura, A, Ventura, S, Versaci, R, Villella, I, Xu, G
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Physics; The physics of elementary particles and fields
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2004.04.012

We have searched for the C-violating decay η→γγγ in a sample of ∼18 million η mesons produced in φ→ηγ decays, collected with the KLOE detector at the Frascati φ-factory DAΦNE. No signal is observed and we obtain the upper limit BR(η→γγγ)⩽1.6×10−5 at 90% CL.