Search for a new gauge boson in $\pi^{0}$ decays

A search was made for a new light gauge boson $X$ which might be produced in $\pi^{0}\rightarrow\gamma + X$ decay from neutral pions generated by 450-GeV protons in the CERN SPS neutrino target. Th e X's would penetrate the downstream shielding and be observed in the NOMAD detector via the Prim...

Descripción completa

Detalles Bibliográficos
Autores principales: Altegoer, J., Astier, P., Autiero, D., Baldisseri, A., Baldo-Ceolin, M., Ballocchi, G., Banner, M., Basa, S., Bassompierre, G., Benslama, K., Besson, N., Bird, I., Blumenfeld, Barry J., Bobisut, F., Bouchez, J., Boyd, S., Bueno, A., Bunyatov, S., Camilleri, L., Cardini, A., Castera, A., Cattaneo, P.W., Cavasinni, V., Cervera-Villanueva, A., Collazuol, G.M., Conforto, G., Conta, C., Contalbrigo, M., Cousins, R., Daniels, D., De Santo, A., Del Prete, T., Dignan, T., Di Lella, L., do Couto e Silva, E., Donnelly, I.J., Dumarchez, J., Fazio, T., Feldman, G.J., Ferrari, R., Ferrere, D., Flaminio, V., Fraternali, M., Gaillard, J-M., Galumian, P., Gangler, E., Geiser, A., Geppert, D., Gibin, D., Gninenko, S.N., Gomez-Cadenas, J.J., Gosset, J., Gossling, C., Gouanere, M., Grant, A., Graziani, G., Guglielmi, A., Hagner, C., Hernando, J., Hubbard, D., Hurst, P., Hyett, N., Iacopini, E., Joseph, C., Kekez, D., Khomenko, B., Kirsanov, M.M., Klimov, O., Kokkonen, J., Kovzelev, A.V., Kuznetsov, V., Lacaprara, S., Lanza, A., La Rotonda, L., Laveder, M., Letessier-Selvon, A., Levy, J-M., Linssen, L., Ljubicic, A., Long, J., Lupi, A., Manola-Poggioli, E., Marchionni, A., Martelli, F., Mechain, X., Mendiburu, J.P., Meyer, J.P., Mezzetto, M., Mishra, S.R., Moorhead, G.F., Mossuz, L., Nedelec, P., Nefedov, Yu., Nguyen-Mau, C., Orestano, D., Pastore, F., Peak, L.S., Pennacchio, E., Perroud, J.P., Pessard, H., Petti, R., Placci, A., Plothow-Besch, H., Pluquet, A., Polesello, G., Pollmann, D., Pope, B.G., Popov, B., Poulsen, C., Rathouit, P., Roda, C., Rubbia, A., Salvatore, F., Scannicchio, D., Schahmaneche, K., Schmidt, B., Sconza, A., Serrano, M., Sevior, M.E., Sillou, D., Soler, F.J.P., Sozzi, G., Steele, D., Steffen, P., Steininger, M., Stiegler, U., Stipcevic, M., Stolarczyk, T., Tareb-Reyes, M., Taylor, G.N., Tereshchenko, S., Toropin, A.N., Touchard, A.M., Tovey, S.N., Tran, M.T., Tsesmelis, E., Ulrichs, J., Uros, V., Valdata-Nappi, M., Valuev, V., Vannucci, F., Varvell, K.E., Veltri, M., Vercesi, V., Verkindt, D., Vieira, J.M., Vinogradova, T., Vo, M.K., Volkov, S.A., Weber, F., Weisse, T., Werlen, M., Wilson, F., Winton, L.J., Yabsley, Bruce D., Zaccone, H., Zuber, K.
Lenguaje:eng
Publicado: 1998
Materias:
Particle Physics - Experiment
Acceso en línea:https://dx.doi.org/10.1016/S0370-2693(98)00402-X
http://cds.cern.ch/record/352170
Descripción
Sumario:A search was made for a new light gauge boson $X$ which might be produced in $\pi^{0}\rightarrow\gamma + X$ decay from neutral pions generated by 450-GeV protons in the CERN SPS neutrino target. Th e X's would penetrate the downstream shielding and be observed in the NOMAD detector via the Primakoff effect, in the process of $X \rightarrow\pi^{0}$ conversion in the external Coulomb field of a nucleus.\ With $1.45\times10^{18}$ protons on target, 20 candidate events with energy between 8 and 140 GeV were found from the analysis of neutrino data.\ This number is in agreement with the e xpectation of 18.1$\pm$2.8 background events from standard neutrino processes.\ A new 90 $\% ~C.L.$ upper limit on the branching ratio $Br(\pi^{0}\rightarrow\gamma + X)<$ (3.3~to~1.9)$\times10^{-5}$ for $X$ masses ranging from 0 to 120 MeV/c$^{2}$ is obtained.

Ejemplares similares