Form factors and semileptonic decay of $D_s^ + \to \phi \bar{\ell}\nu$ from QCD sum rule

Abstract

We calculate $D_s^+\to \phi$ transition form factors $V$, $A_0$, $A_1$ and $A_2$, and study semileptonic decay of $D_s^+\to \phi \bar{\ell}\nu$ based on QCD sum rule method. We compare our results of the ratios of $V(0)/A_1(0)$, $A_2(0)/A_1(0)$, $\Gamma_L/\Gamma_T$, and the total decay branching ratio of $D_s^+\to \phi \bar{\ell}\nu$ with experimental data, and find that they are consistent.