D_s^{*} rightarrow phi helicity form factors and the exclusive weak decays

Abstract

The decay width of the D_s^{*} meson is dominated by the electromagnetic mode D_s^*rightarrow D_s gamma , 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 helicity form factors and discuss the experiment potential of discovering exclusive 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}, varGamma _{D_s^*rightarrow phi l nu } = (3.28^{+0.82}_{-0.71}) times 10^{-14} , textrm{GeV}, varGamma _{D_s^{*} rightarrow phi pi } = ( 3.81^{+1.52}_{-1.33} ) times 10^{-14} , textrm{GeV} and varGamma _{D_s^{*}rightarrow phi rho } = ( 1.16^{+0.42}_{-0.39} ) times 10^{-13} , textrm{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.