Measurement of the decay rate and form factor parameter αK* in the decay KL → e+e-γ

V. Fanti*, A. Lai, L. Musa, D. Marras, A. Nappi, B. Hay, R. W. Moore, K. N. Moore, D. J. Munday, M. D. Needham, M. A. Parker, T. O. White, S. A. Wotton, G. Barr, G. Bocquet, J. Bremer, A. Ceccucci, D. Cundy, N. Doble, W. FunkL. Gatignon, A. Gianoli, A. Gonidec, G. Govi, P. Grafström, W. Kubischta, A. Lacourt, S. Luitz, G. Kesseler, J. P. Matheys, A. Norton, S. Palestini, B. Panzer-Steindel, D. Schinzel, H. Taureg, M. Velasco, O. Vossnack, H. Wahl, G. Wirrer, V. Kekelidze, A. Mestvirishvili, G. Tatishvili, I. Potrebenikov, A. Tkatchev, A. Zinchenko, O. Boyle, V. J. Martin, I. G. Knowles, H. L C Parsons, P. Dalpiaz, J. Duclos, P. L. Frabetti, M. Martini, F. Petrucci, M. Porcu, M. Savrié, A. Bizzeti, M. Calvetti, G. Collazuol, G. Graziani, E. Iacopini, M. Lenti, A. Michetti, H. G. Becker, H. Blümer, P. Buchholz, D. Coward, C. Ebersberger, H. Fox, A. Kalter, K. Kleinknecht, U. Koch, L. Köpke, B. Renk, J. Scheidt, J. Schmidt, V. Schönharting, Y. Schué, R. Wilhelm, A. Winhart, M. Wittgen, J. C. Chollet, S. Crépé, L. Iconomidou-Fayard, L. Fayard, J. Ocariz, G. Unal, D. Vattolo, I. Wingerter, G. Anzivino, P. Cenci, P. Lubrano, M. Pepe, B. Gorini, P. Calafiura, R. Carosi, C. Cerri, M. Cirilli, F. Costantini, R. Fantechi, S. Giudici, I. Mannelli, G. Pierazzini, M. Sozzi, J. B. Cheze, J. Cogan, M. de Beer, P. Debu, A. Formica, R. Granier de Cassagnac, P. Hristov, E. Mazzucato, B. Peyaud, S. Schanne, R. Turlay, B. Vallage, I. Augustin, M. Bender, M. Holder, M. Ziolkowski, R. Arcidiacono, C. Biino, F. Marchetto, E. Menichetti, J. Nassalski, E. Rondio, M. Szleper, W. Wislicki, S. Wronka, H. Dibon, G. Fischer, M. Jeitler, M. Markytan, I. Mikulec, G. Neuhofer, M. Pernicka, A. Taurok

*Corresponding author for this work

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21 Scopus citations

Abstract

The decay rate of the neutral K meson KL → e+e-γ has been measured with the NA48 detector at the CERN SPS. A total of 6864 events has been observed with an estimated background of 10 events. The branching ratio is Γ(KL → e+e-γ)/Γ(KL → all) = (1.06 ± 0.02stat ± 0.02sys ± 0.04calc) × 10-5 The parameter αK* describing the relative strength of the two contributing amplitudes to this decay through intermediate pseudoscalar or vector mesons was measured to be αK* = -0.36 ± 0.06stat ± 0.02sys.

Original languageEnglish (US)
Pages (from-to)553-563
Number of pages11
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Volume458
Issue number4
DOIs
StatePublished - 1999

ASJC Scopus subject areas

  • Nuclear and High Energy Physics

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