Semileptonic Decay of $D_s^+\to π^0 \ell^+ ν_\ell$ Via Neutral Meson Mixing

Abstract

Based on the mechanism of neutral meson mixing, we predict the branching fraction of the semileptonic decay of D + s → π 0 ℓ + ν ℓ (ℓ = e, µ) using recently measured branching fraction of D + s → ηe + νe by BESIII experiment . We also give a formula that can describe the neutral meson mixing of π 0 , η, η ′ and a pseudoscalar gluonium G in a unified way. The predicted branching fraction of D + s → π 0 e + νe decay is B(D + s → π 0 e + νe) = (2.65 ± 0.38) × 10 −5 . It is important to search for the decay D + s → π 0 ℓ + ν ℓ in experiment, in order to understand the mechanism of π 0 production in D + s → π 0 transition in semileptonic decay. We also estimate the branching fraction of D + s → π 0 τ + ντ , which is the only kinematically allowed semi-tauonic decay mode of the charmed meson, since the mass value of D + s meson is just slightly above the threshold of π 0 τ + generation in the semi-tauonic decay.