Measurements of the branching fractions for the semi-leptonic decays $D^+_s\to\phi e^{+}\nu_{e}$, $\phi \mu^{+}\nu_{\mu}$, $\eta \mu^{+}\nu_{\mu}$ and $\eta'\mu^{+}\nu_{\mu}$

Abstract

By analyzing 482 pb−1 of e+e− collision data collected at the center-of-mass energy s=4.009 GeV with the BESIII detector, we measure the %absolute branching fractions for the semi-leptonic decays Ds+→ϕe+νe, ϕμ+νμ, ημ+νμ and η′μ+νμ to be B(Ds+→ϕe+νe)=(2.26±0.45±0.09)%, B(Ds+→ϕμ+νμ)=(1.94±0.53±0.09)%, B(Ds+→ημ+νμ)=(2.42±0.46±0.11)% and B(Ds+→η′μ+νμ)=(1.06±0.54±0.07)%, where the first and second uncertainties are statistical and systematic, respectively. The branching fractions for the three semi-muonic decays Ds+→ϕe+νe, ϕμ+νμ, ημ+νμ and η′μ+νμ are determined for the first time and that of Ds+→ϕe+νe is consistent with the world average value within uncertainties.