The weak radiative decay Xi(o) -> Lambda e(+)e(-) has been detected for the first time. We find 412 candidates in the signal region, with an estimated background of 15 +/- 5 events. We determine the branching fraction B(Xi(o) -> Lambda e(+)e(-)) = [7.6 +/- 0.4(stat) +/- 0.4(syst) +/- 0.2 (norm)] x 10(-6), consistent with an internal bremsstrahlung process, and the decay asymmetry parameter alpha(Xi) Lambda(ee) = -0.8 +/- 0.2, consistent with that of Xi(o) -> Lambda gamma. The charge conjugate reaction (Xi(o)) over bar -> (Lambda) over bare(+)e(-) has also been observed. (c) 2007 Elsevier B.V.. All rights reserved.

First observation and branching fraction and decay parameter measurements of the weak radiative decay Xi(0)->Lambda e(+)e-

LAMANNA, GIANLUCA;COSTANTINI, FLAVIO;GIUDICI, SERGIO;SOZZI, MARCO STANISLAO;
2007-01-01

Abstract

The weak radiative decay Xi(o) -> Lambda e(+)e(-) has been detected for the first time. We find 412 candidates in the signal region, with an estimated background of 15 +/- 5 events. We determine the branching fraction B(Xi(o) -> Lambda e(+)e(-)) = [7.6 +/- 0.4(stat) +/- 0.4(syst) +/- 0.2 (norm)] x 10(-6), consistent with an internal bremsstrahlung process, and the decay asymmetry parameter alpha(Xi) Lambda(ee) = -0.8 +/- 0.2, consistent with that of Xi(o) -> Lambda gamma. The charge conjugate reaction (Xi(o)) over bar -> (Lambda) over bare(+)e(-) has also been observed. (c) 2007 Elsevier B.V.. All rights reserved.
2007
Batley, Jr; Kalmus, Ge; Lazzeroni, C; Munday, Dj; Patel, M; Slater, Mw; Wotton, Sa; Arcidiacono, R; Bocquet, G; Ceccucci, A; Cundy, D; Doble, N; Falaleev, V; Gatignon, L; Gonidec, A; Grafstrom, P; Kubischta, W; Mikulec, I; Norton, A; Panzer Steindel, B; Rubin, P; Wahl, H; Goudzovski, E; Hristov, P; Kekelidze, V; Litov, L; Madigozhin, D; Molokanova, N; Potrebenikov, Y; Stoynev, S; Zinchenko, A; Monnier, E; Swallow, E; Winston, R; Sacco, R; Walker, A; Baldini, W; Dalplaz, P; Frabetti, Pl; Gianoli, A; Martini, M; Petrucci, F; Savrie, M; Scarpa, M; Bizzeti, A; Calvetti, M; Collazuol, G; Iacopini, E; Lenti, M; Ruggiero, G; Veltri, M; Behler, M; Eppard, K; Eppard, M; Hirstius, A; Kleinknecht, K; Koch, U; Marouelli, P; Masetti, L; Moosbrugger, U; Morales, Cm; Peters, A; Wanke, R; Winhart, A; Dabrowski, A; Martin, Tf; Velasco, M; Anzivino, G; Cenci, P; Imbergamo, E; Lamanna, Gianluca; Lubrano, P; Michetti, A; Nappi, A; Pepe, M; Petrucci, Mc; Piccini, M; Valdata, M; Cerri, C; Costantini, Flavio; Fantechi, R; Fiorini, L; Giudici, Sergio; Marinelli, ; Pierazzini, G; Sozzi, MARCO STANISLAO; Cheshkov, C; Cheze, Jb; De Beer, A; Debu, P; Gouge, G; Marel, G; Mazzucato, E; Peyaud, B; Vallage, B; Holder, M; Maier, A; Ziolkowski, M; Biino, C; Cartiglia, N; Clernencic, A; Lopez, Sg; Marchetto, E; Menichetti, E; Pastrone, N; Wislicki, W; Dibon, H; Jeitler, M; Markytan, M; Neuhofer, G; Widhalrn, L.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/180365
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