$$D_s^{*} \rightarrow \phi $$ D s ∗ → ϕ helicity form factors and the exclusive weak decays

Abstract The decay width of the $$D_s^{*}$$ D s ∗ meson is dominated by the electromagnetic mode $$D_s^*\rightarrow D_s \gamma $$ D s ∗ → D s γ , and it is thus the longest-lived charged vector meson. In light of this point, we perform the first QCD LCSRs calculation of $$D_s^{*}\rightarrow \phi $$ D s ∗ → ϕ helicity form factors and discuss the experiment potential of discovering exclusive $$D_s^{*}$$ D s ∗ weak decays. The main result is the partial decay widths, which read as $$\varGamma _{D_s^*\rightarrow l \nu } = 2.44 \times 10^{-12} \, \textrm{GeV}$$ Γ D s ∗ → l ν = 2.44 × 10 - 12 GeV , $$\varGamma _{D_s^*\rightarrow \phi l \nu } = (3.28^{+0.82}_{-0.71}) \times 10^{-14} \, \textrm{GeV}$$ Γ D s ∗ → ϕ l ν = ( 3 . 28 - 0.71 + 0.82 ) × 10 - 14 GeV , $$\varGamma _{D_s^{*} \rightarrow \phi \pi } = ( 3.81^{+1.52}_{-1.33} ) \times 10^{-14} \, \textrm{GeV}$$ Γ D s ∗ → ϕ π = ( 3 . 81 - 1.33 + 1.52 ) × 10 - 14 GeV and $$\varGamma _{D_s^{*}\rightarrow \phi \rho } = ( 1.16^{+0.42}_{-0.39} ) \times 10^{-13} \, \textrm{GeV}$$ Γ D s ∗ → ϕ ρ = ( 1 . 16 - 0.39 + 0.42 ) × 10 - 13 GeV . We show that these channels are promising in the near future, serving as the first experimental observation of weak decays of a vector meson, and would open up a new playground for precision test of the standard model.