Observation of the decay K-S -> pi(+)pi(-)e(+)e(-)

Authors
Lai, A Marras, D Musa, L Bevan, A Dosanjh, RS Gershon, TJ Hay, B Kalmus, GE Munday, DJ Needham, MD Olaiya, E Parker, MA White, TO Wotton, SA Barr, G Blumer, H Bocquet, G Ceccucci, A Cundy, D D'Agostini, G Doble, N Falaleev, V Gatignon, L Gonidec, A Govi, G Grafstrom, P Kubischta, W Lacourt, A Norton, A Palestini, S Panzer-Steindel, B Peyaud, B Taureg, H Velasco, M Wahl, H Cheshkov, C Hristov, P Kekelidze, V Madigojine, D Mestvirishvili, A Molokanova, N Potrebenikov, Y Tatishvili, G Tkatchev, A Zinchenko, A Knowles, I Martin, V Parsons, H Sacco, R Lazzeroni, C Walker, A Contalbrigo, M Dalpiaz, P Duclos, J Frabetti, PL Gianoli, A Martini, H Petrucci, F Savrie, M Bizzeti, A Calvetti, M Collazuol, G Graziani, G Iacopini, E Lenti, M Becker, HG Eppard, M Fox, H Holtz, K Kalter, A Kleinknecht, K Koch, U Kopke, L Pellmann, I Peters, A Renk, B Schmidt, SA Schonharting, V Schue, Y Winhart, A Wittgen, M Chollet, JC Crepe, S Fayard, L Iconomidou-Fayard, L Ocariz, J Unal, G Wingerter-Seez, I Anzivino, G Cenci, P Imbergamo, E Lubrano, P Nappi, A Pepe, M Piccini, M Carosi, R Casali, R Cerri, C Cirilli, M Costantini, F Fantechi, R Giudici, S Gorini, B Mannelli, I Pierazzini, G Sozzi, M Cheze, JB Cogan, J De Beer, M Debu, P Formica, A de Cassagnac, RG Mazzucato, E Turlay, R Vallage, B Augustin, I Bender, M Holder, M Ziolkowski, M Arcidiacono, R Biino, C Marchetto, F Menichetti, E Pastrone, N Nassalski, J Rondio, E Szleper, M Wislicki, W Wronka, S Dibon, H Fischer, G Jeitler, M Markytan, M Mikulec, I Neuhofer, G Pernicka, M Taurok, A
Citation
A. Lai et al., Observation of the decay K-S -> pi(+)pi(-)e(+)e(-), PHYS LETT B, 496(3-4), 2000, pp. 137-144
Citations number
15
Categorie Soggetti
Physics
Journal title
PHYSICS LETTERS B
ISSN journal
03702693 → ACNP
Volume
496
Issue
3-4
Year of publication
2000
Pages
137 - 144
Database
ISI
SICI code
0370-2693(200012)496:3-4<137:OOTDK->2.0.ZU;2-E
Abstract
We present the first observation of the decay K-S -> pi (+)pi (-)e(+)e(-) b ased upon the data collected in 1998 by the NA48 experiment at CERN. We hav e identified a clean sample of 56 events with negligible background contami nation. Using K-L -> pi (+)pi (-)pi (0)(D) decays as normalization sample, the branching ratio is measured to be BR(K-S -> pi (+)pi (-)e(+)e(-)) = [4. 5 +/- 0.7(stat) +/- 0.4(syst)] x 10(-5). This result is in good agreement w ith the theoretical expectations from the mechanism of inner bremsstrahlung . (C) 2000 Elsevier Science B.V. All rights reserved.