Improved measurement of the semileptonic decay $D^+_{s}\to K^0 e^+\nu_e$

TL;DR

This paper reports precise measurements of the branching fraction and form factor for the semileptonic decay $D_s^+ o K^0 e^+ u_e$, improving the accuracy over previous results using BESIII data.

Contribution

The study provides more precise measurements of the branching fraction and form factor for $D_s^+ o K^0 e^+ u_e$ decay, enhancing the understanding of charm semileptonic decays.

Findings

Branching fraction measured as (2.98±0.23±0.12)×10^{-3}

Form factor at zero momentum transfer determined as 0.636±0.049±0.013

Results are 1.6 and 1.7 times more precise than previous world averages

Abstract

Analyzing $e^+e^-$ collision data corresponding to an integrated luminosity of $7.33~\mathrm{fb}^{-1}$ collected at center-of-mass energies between 4.128 and 4.226~GeV with the BESIII detector, we measure the branching fraction of the semileptonic decay $D^+_{s}\to K^0 e^+\nu_e$ to be $(2.98\pm0.23\pm0.12)\times10^{-3}$. The $D_s^+\to K^0$ hadronic form factor is determined from the differential decay rate of $D^+_s\to K^0 e^+\nu_e$ to be $f^{K^0}_+(0)=0.636\pm0.049\pm0.013$. For both measurements, the first uncertainty is statistical and the second systematic. The branching fraction and form factor measurements are factors of 1.6 and 1.7 more precise than the previous world averages, respectively.