Using the NA48 detector at the CERN SPS, 31 K-S --> pi(0)gammagamma candidates with an estimated background of 13.7 +/- 3.2 events have been observed. This first observation leads to a branching ratio of BR(K-S --> pi(0)gammagamma)(z>0.2) = (4.9 +/- 1.6(stat) +/- 0.9(syst)) x 10(-8) in agreement with Chiral Perturbation Theory predictions. (C) 2003 Elsevier B.V. All rights reserved.
First observation of the K-S -> pi(0)gamma gamma decay
COSTANTINI, FLAVIO;GIUDICI, SERGIO;SOZZI, MARCO STANISLAO;
2004-01-01
Abstract
Using the NA48 detector at the CERN SPS, 31 K-S --> pi(0)gammagamma candidates with an estimated background of 13.7 +/- 3.2 events have been observed. This first observation leads to a branching ratio of BR(K-S --> pi(0)gammagamma)(z>0.2) = (4.9 +/- 1.6(stat) +/- 0.9(syst)) x 10(-8) in agreement with Chiral Perturbation Theory predictions. (C) 2003 Elsevier B.V. All rights reserved.File in questo prodotto:
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