We present the first observation of the decay K(S) --> pi+ pi- e+ e- based upon the data collected in 1998 by the NA48 experiment at CERN. We have identified a clean sample of 56 events with negligible background contamination. Using K(L) --> pi+ pi- pi0D 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 with the theoretical expectations from the mechanism of inner bremsstrahlung.
Observation of the decay K(S) --> pi+ pi- e+ e-
ANZIVINO, Giuseppina;IMBERGAMO, ERMANNO;NAPPI, Aniello;PICCINI, Mauro
2000
Abstract
We present the first observation of the decay K(S) --> pi+ pi- e+ e- based upon the data collected in 1998 by the NA48 experiment at CERN. We have identified a clean sample of 56 events with negligible background contamination. Using K(L) --> pi+ pi- pi0D 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 with the theoretical expectations from the mechanism of inner bremsstrahlung.File in questo prodotto:
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