# Search for the decay ${D}_{s}^{+}\to \gamma {e}^{+}{\nu }_{e}$

10 April 2019

Abstract: A search for the rare radiative leptonic decay ${D}_{s}^{+}\to \gamma {e}^{+}{\nu }_{e}$ is performed for the first time using electron-positron collision data corresponding to an integrated luminosity of $3.19\text{}\text{}{\mathrm{fb}}^{-1}$, collected with the BESIII detector at a center-of-mass energy of 4.178 GeV. No evidence for the ${D}_{s}^{+}\to \gamma {e}^{+}{\nu }_{e}$ decay is seen, and an upper limit of $B\left({D}_{s}^{+}\to \gamma {e}^{+}{\nu }_{e}\right)<1.3×1{0}^{-4}$ is set on the partial branching fraction at a 90% confidence level for radiative photon energies ${E}_{\gamma }^{*}>0.01\text{}\text{}\mathrm{GeV}$.

Published in: Physical Review D 99 (2019)