Cargando…

Recent NA48/2 results on rare kaon decays

NA48/2 results contributing to ChPT testing are presented. A sample of 1663 events of the rare decay $K^{\pm}$ $\to$ $\mu^{\pm} ν e^+e^-$ has been selected with a minimum $e^+e^-$ effective mass of 140 MeV. The measured model independent decay rate is in agreement with ChPT predictions. The branchin...

Descripción completa

Detalles Bibliográficos
Autor principal: Madigozhin, Dmitry
Lenguaje:eng
Publicado: 2019
Materias:
Acceso en línea:https://dx.doi.org/10.1051/epjconf/201920605001
http://cds.cern.ch/record/2836368
Descripción
Sumario:NA48/2 results contributing to ChPT testing are presented. A sample of 1663 events of the rare decay $K^{\pm}$ $\to$ $\mu^{\pm} ν e^+e^-$ has been selected with a minimum $e^+e^-$ effective mass of 140 MeV. The measured model independent decay rate is in agreement with ChPT predictions. The branching ratio of the $K^{\pm} \to \pi^{\pm} \pi^0 e^+ e^-$ decay, never observed so far, has been obtained from a sample of about 5000 candidates with less than 6% background, also in agreement with ChPT predictions. In addition, a most precise measurement of the charged kaon semileptonic form factors has been obtained from 4.4 million $K_{e3}$ and 2.3 million $K_{{\mu} 3}$ events collected in 2004.