Search for the semileptonic decay $D_s^+\to \pi^0e^+\nu_e$

TL;DR

This paper reports the first search for the semileptonic decay $D_s^+ o ^0 e^+ u_e$ using BESIII data, setting an upper limit on its branching fraction and exploring $^0$--$$ mixing effects.

Contribution

It is the first experimental search for the decay $D_s^+ o ^0 e^+ u_e$, providing an upper limit on its branching fraction.

Findings

No significant signal observed.

Upper limit on branching fraction set at $6.4 imes 10^{-5}$.

Results constrain $^0$--$$ mixing models.

Abstract

We present the first search for the semileptonic decay $D_s^+\to \pi^0 e^+\nu_e$ using a data sample of electron-positron collisions recorded with the BESIII detector at center-of-mass energies between 4.178 and 4.226~GeV, corresponding to an integrated luminosity of 6.32~fb$^{-1}$. This decay is expected to be sensitive to $\pi^0$--$\eta$ mixing. No significant signal is observed. We set an upper limit of $6.4 \times 10^{-5}$ on the branching fraction at the $90\%$ confidence level.