Observation of the rare decay $K_{S} \rightarrow \pi^0 e^{+}e^{-}$

A search for the decay $K_{S} \rightarrow \pi^0 e^{+}e^{-}$ has been made by the NA48/1 experiment at the CERN SPS accelerator. Using data collected during 89 days in 2002 with a high-intensity $K_{S}$ beam, 7 events were found with a background of 0.15 events. The branching fraction $BR(K_{S} \righ...

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Detalles Bibliográficos
Autores principales: Batley, J.R., Kalmus, G.E., Lazzeroni, C., Munday, D.J., Patel, M., Slater, M.W., Wotton, S.A., Arcidiacono, R., Bocquet, G., Ceccucci, A., Cundy, D., Doble, N., Falaleev, V., Gatignon, L., Gonidec, A., Grafstrom, P., Kubischta, W., Marchetto, F., Mikulec, I., Norton, A., Panzer-Steindel, B., Rubin, P., Wahl, H., Goudzovski, E., Gurev, D., Hristov, P., Kekelidze, V., Litov, L., Madigozhin, D., Molokanova, N., Potrebenikov, Yu., Stoynev, S., Zinchenko, A., Monnier, E., Swallow, E., Winston, R., Sacco, R., Walker, A., Baldini, W., Dalpiaz, P., Frabetti, P.L., Gianoli, A., Martini, M., Petrucci, F., Scarpa, M., Savrie, M., Bizzeti, A., Calvetti, M., Collazuol, G., Graziani, G., Iacopini, E., Lenti, M., Martelli, F., Ruggiero, G., Veltri, M., Behler, M., Eppard, K., Eppard, M., Hirstius, A., Kleinknecht, K., Koch, U., Masetti, L., Marouelli, P., Moosbrugger, U., Morales Morales, C., Peters, A., Wanke, R., Winhart, A., Dabrowski, A., Fonseca Martin, T., Goy Lopez, S., Velasco, M., Anzivino, G., Cenci, P., Imbergamo, E., Lamanna, G., Lubrano, P., Michetti, A., Nappi, A., Pepe, M., Petrucci, M.C., Piccini, M., Valdata, M., Cerri, C., Costantini, F., Fantechi, R., Fiorini, L., Giudici, S., Mannelli, I., Pierazzini, G., Sozzi, M., Cheshkov, C., Cheze, J.B., De Beer, M., Debu, P., Gouge, G., Marel, G., Mazzucato, E., Peyaud, B., Vallage, B., Holder, M., Maier, A., Ziolkowski, M., Biino, C., Cartiglia, N., Clemencic, M., Menichetti, Ezio A., Pastrone, N., Wislicki, W., Dibon, H., Jeitler, M., Markytan, M., Neuhofer, G., Widhalm, L.
Lenguaje:eng
Publicado: 2003
Materias:
Particle Physics - Experiment
Acceso en línea:https://dx.doi.org/10.1016/j.physletb.2003.10.001
http://cds.cern.ch/record/645655
Descripción
Sumario:A search for the decay $K_{S} \rightarrow \pi^0 e^{+}e^{-}$ has been made by the NA48/1 experiment at the CERN SPS accelerator. Using data collected during 89 days in 2002 with a high-intensity $K_{S}$ beam, 7 events were found with a background of 0.15 events. The branching fraction $BR(K_{S} \rightarrow \pi^0 e^{+}e^{-}, m_{ee} > 0.165$ GeV/c$^{2}) = (3.0^{+1.5}_{-1.2(stat)} \pm 0.2(syst)) \times 10^{-9}$ has been measured. Using a vector matrix element and a form factor equal to one, the measurement gives $BR(K_{S} \rightarrow \pi^0 e^{+}e^{-}) = (5.8^{+2.9}_{-2.4}) \times 10^{-9}$.

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