Factorization and Decay Constants $f_{D_s^{\ast }}$ and $f_{D_s}$

Abstract

We calculate the decay constants of $D_s$ and $D_s^{\ast }$ with ${\bar{B}}^0\text{ra}{D}^{+}{\ell }^{-}\nu$ and ${\bar{B}}^0\text{ra}{D}^{+}{D}_s^{-(\ast )}$ decays. In our analysis we take the factorization method including non-factorizable term contributions and used two different form factor behaviours (constant and monopole-type) for $F_0(q^2)$. We also consider the QCD-penguin and Electroweak-penguin contributions in hadronic decays within the NDR renormalization scheme at NLO calculation. We estimate the decay constant of the $D_s$ meson to be $233\pm 49$ $\mathrm{MeV}$ for (pole/pole)-type form factor and $255\pm 54$ $\mathrm{MeV}$ for (pole/constant)-type form factor. For $D_s^{\ast }$ meson, we get $f_{D_s^{\ast }}=346\pm 82$ $\mathrm{MeV}$, and $f_{D_s^{\ast }}/f_{D_s}=1.43\pm 0.45$ for (pole/constant)-type form factor.

Comments: Latex file, 18 pages, no figure