A study of the $K^{+}\to {\pi }^0{e}^{+}\nu \gamma$ decay

Abstract

A sample of $1.3\times 10^5$ $K^{+}\to {\pi }^0{e}^{+}\nu \gamma$ candidates with less than 1% background was collected by the NA62 experiment at the CERN SPS in 2017-2018. Branching fraction measurements are obtained at percent relative precision in three restricted kinematic regions, improving on existing results by a factor larger than two. An asymmetry, possibly related to T-violation, is investigated with no evidence observed within the achieved precision.