Speaker
Radoslav Marchevski
(CERN)
Description
The NA48/2 experiment at CERN collected a very large sample of charged kaon decays into multiple final states. From this data sample we have reconstructed about 1500 events of the very rare decay K+- —>mu+- nu e+ e- over almost negligible background in the region with m(e+e-) above 140 MeV, which is of great interest in Chiral Perturbation Theory. We present the m_ee spectrum and a model-independent measurement of the decay rate for this region.