Measurement of the form factors of charged kaon semileptonic decays

Abstract

A measurement of the form factors of charged kaon semileptonic decays is presented, based on $4.4 \times 10^6$ $K^\pm \to π^0 e^\pm ν_e$ ($K^\pm_{e3}$) and $2.3 \times 10^6$ $K^\pm \to π^0 μ^\pm ν_μ$ ($K^\pm_{\mu3}$) decays collected in 2004 by the NA48/2 experiment. The results are obtained with improved precision as compared to earlier measurements. The combination of measurements in the $K^\pm_{e3}$ and $K^\pm_{\mu3}$ modes is also presented.