Measurement of the branching ratio and form factors for the decay K L → π±π0e ∓νe(ν̄e)

Batley, J. R.; Dosanjh, R. S.; Gershon, T. J.; Kalmus, G. E.; Lazzeroni, C.; Munday, D.; Olaiya, E.; Patel, M.; Parker, M. A.; White, T. O.; Wotton, S. A.; Arcidiacono, R.; Bocquet, G.; Ceccucci, A.; Cuhadar Donszelmann, T.; Cundy, D.; Doble, N.; Falaleev, V.; Gatignon, L.; Gonidec, A.; Gorini, B.; Grafstrom, P.; Kubischta, W.; Mikulec, I.; Norton, A.; Palestini, S.; Wahl, H.; Cheshkov, C.; Hristov, P.; Kekelidze, V.; Litov, L.; Madigozhin, D.; Molokanova, N.; Potrebenikov, Y.; Zinchenko, A.; Rubin, P.; Sacco, R.; Walker, A.; Bettoni, D.; Calabrese, R.; Dalpiaz, P.; Duclos, J.; Frabetti, P. L.; Gianoli, A.; Martini, M.; Masetti, L.; Petrucci, E.; Savrie, M.; Scarpa, M.; Bizzeti, A.; Calvetti, M.; Collazuol, Gianmaria; Iacopini, E.; Lenti, M.; Martelli, F.; Ruggiero, G.; Veltri, M.; Eppard, K.; Eppard, M.; Hirstius, A.; Kleinknecht, K.; Koch, U.; Kopke, L.; P. L., Da; Marouelli, P.; Mestvirishvili, I.; Morales, C.; Pellmann, I.; Peters, A.; Renk, B.; Schmidt, S. A.; Schonharting, V.; Wanke, R.; Winhart, A.; Chollet, J. C.; Fayard, L.; Graziani, G.; Iconomidou Fayard, L.; Unal, G.; Wingerter Seez, I.; Anzivino, G.; Cenci, P.; Imbergamo, E.; Lamanna, G.; Lubrano, P.; Mestvirishvili, A.; Michetti, A.; Nappi, A.; Pepe, M.; Piccini, M.; Valdata Nappi, M.; Casali, R.; Cerri, C.; Cirilli, M.; Costantini, F.; Fantechi, R.; Fiorini, L.; Giudici, S.; Mannelli, I.; Pierazzini, G.; Sozzi, M.; Cheze, J. B.; Beer, M. D.; Debu, P.; Derue, F.; Formica, A.; Gouge, G.; Marel, G.; Mazzucato, E.; Peyaud, B.; Turlay, R.; Vallage, B.; Holder, M.; Maier, A.; Ziolkowski, M.; Biino, C.; Cartiglia, N.; Clemencic, M.; Marchetto, F.; Menichetti, E.; Pastrone, N.; Nassalski, J.; Rondio, E.; Wislicki, W.; Wronka, S.; Dibon, H.; Jeitler, M.; Markytan, M.; Neuhofer, G.; Pernicka, M.; Taurok, A.; Widhalm, L.

doi:10.1016/j.physletb.2004.05.026

The K-L --> pi(+/-)pi(0)e(-/+)v(e) ((v) over bar (e)) decay was investigated with the NA48 detector at CERN SPS using a beam of long-lived neutral kaons. The branching ratio Br(K-L --> pi(+/-)pi(0)e(-/+)v(e)((v) over bar (e)) = (5.21 +/- 0.07(stat) +/-0.09(syst)) x 10(-5) was fixed from a sample of 5464 events with 62 background events. The form factors (f) over bar (s), (f) over bar (p), lambda(g) and (h) over bar were found to be in agreement with previous measurements but with higher accuracy. The coupling parameter of the chiral Lagrangian L-3 = (-4.1 +/- 0.2) x 10(-3) was evaluated from the data. (C) 2004 Elsevier B.V. All rights reserved.