First observation of the KS->pi0 gamma gamma decay
arXiv:hep-ex/0309022 · doi:10.1016/j.physletb.2003.10.073
Abstract
Using the NA48 detector at the CERN SPS, 31 KS->pi0 gamma gamma candidates with an estimated background of 13.7 +- 3.2 events have been observed. This first observation leads to a branching ratio of BR(KS->pi0 gamma gamma) = (4.9 +- 1.6(stat) +- 0.9(syst)) x 10^-8 in agreement with Chiral Perturbation theory predictions.
10 pages, 4 figures submitted to Phys. Lett. B