Search for the K_S -> e+e- decay with the KLOE detector
hep-ex
/ Authors
The KLOE Collaboration, F. Ambrosino, A. Antonelli, M. Antonelli, F. Archilli, P. Beltrame, G. Bencivenni, S. Bertolucci, C. Bini, C. Bloise
and 56 more authors
S. Bocchetta, F. Bossi, P. Branchini, P. Campana, G. Capon, D. Capriotti, T. Capussela, F. Ceradini, P. Ciambrone, F. Crucianelli, E. De Lucia, A. De Santis, P. De Simone, G. De Zorzi, A. Denig, A. Di Domenico, C. Di Donato, B. Di Micco, M. Dreucci, G. Felici, M. L. Ferrer, S. Fiore, P. Franzini, C. Gatti
/ Abstract
We present the result of a direct search for the decay K_S -> e+e-, obtained with a sample of e+e- -> phi -> K_S K_L events produced at DAFNE, the Frascati phi-factory, for an integrated luminosity of 1.9 fb^-1. The search has been performed using a pure K_S beam tagged by the simultaneous detection of a K_L interaction in the calorimeter. Background rejection has been optimized by using both kinematic and particle identification cuts. We find BR(K_S -> e+e-) < 9x10^-9 at 90% CL, which improves by an order of magnitude on the previous best limit.