Precise measurements of the $K_{S} \to \gamma\gamma$ and $K_{L} \to \gamma\gamma$ decay rates

• Published in: Physics letters. B Vol. 551; pp. 7 - 15
• Main Authors: Lai, A., Marras, D., Batley, J R., Dosanjh, R S., Gershon, T J., Kalmus, G E., Lazzeroni, C., Munday, D J., Olaiya, E., Parker, M A., White, T O., Wotton, S A., Arcidiacono, R., Barr, G., Bocquet, G., Ceccucci, A., Cuhadar-Donszelmann, T., Cundy, D., Doble, N., Falaleev, V., Gatignon, L., Gonidec, A., Gorini, B., Grafstrom, P., Kubischta, W., Lacourt, A., Mikulec, I., Norton, A., Panzer-Steindel, B., Tatishvili, G., Wahl, H., Cheshkov, C., Khristov, P Z., Kekelidze, V D., Madigojine, D., Molokanova, N., Potrebenikov, Yu, Zinchenko, A., Martin, V., Rubin, P., Sacco, R., Walker, A., Contalbrigo, M., Dalpiaz, P., Duclos, J., Frabetti, P L., Gianoli, A., Martini, M., Petrucci, F., Savrie, M., Bizzeti, A., Calvetti, M., Collazuol, G., Graziani, G., Iacopini, E., Lenti, M., Martelli, F., Veltri, M., Eppard, M., Hirstius, A., Holtz, K., Kleinknecht, K., Koch, U., Kopke, L., Lopesda, P., Marouelli, P., Mestvirishvili, I., Pellmann, I., Peters, A., Schmidt, S A., Schonharting, V., Schue, Y., Wanke, R., Winhart, A., Wittgen, M., Chollet, J C., Fayard, L., Iconomidou-Fayard, L., Unal, G., Wingerter-Seez, I., Anzivino, G., Cenci, P., Imbergamo, E., Lubrano, P., Mestvirishvili, A., Nappi, A., Pepe, M., Piccini, M., Casali, R., Cerri, C., Cirilli, M., Costantini, F., Fantechi, R., Fiorini, L., Giudici, S., Mannelli, I., Pierazzini, G., Sozzi, M., Cheze, J B., de Beer, M.
• Format: Journal Article
• Language: English
• Published: Elsevier 2003
• Subjects: High Energy Physics - Experiment; Physics
• ISSN: 0370-2693

Affiliations: CERN Imprint: 10 Oct 2002 Pages: 10 p Subjects: Particle Physics - Experimental Results Accelerator: CERN SPS Experiment: NA48 (CERN Expt. Grey Book) ; Divisional affiliation: EP See record at SLAC Abstract: The K_S -> gammagamma decay rate has been measured with the NA48 detector using a high intensity short neutral beam from the CERN SPS. The measured branching ratio BR(K_S) -> gammagamma = (2.78 +- 0.06_{stat} +- 0.04_{syst}) x 10^{-6}, obtained from 7461 +- 172 K_S -> gammagamma events, is significantly higher than the O(p^4) prediction of Chiral Perturbation Theory. Using a K-L beam the ratio Gamma(K_L-gammagamma / Gamma(K_L -> pi^0pi^0pi^0 = (2.81 +- 0.01_{stat} +- 0.02_{syst}) x 10^{-3} has been measured.