Study of scalar meson f_0(980) and K_0^*(1430) from B \to f_0(980)\rho(\omega, \phi) and B \to K^*_0(1430)\rho(\omega) Decays

In the two-quark model supposition for $f_0(980)$ and $K_0^{*}(1430)$, the branching ratios and the direct CP-violating asymmetries for decays $\bar{B}^0\to f_0(980)\rho^0(\omega,\phi), K^{*0}_0(1430)\rho^0(\omega), K^{*-}_0(1430)\rho^+$ and $B^-\to f_0(980)\rho^-, K^{*0}_0(1430)\rho^-, K^{*-}_0(1430)\rho^0(\omega)$ are studied by employing the perturbative QCD (PQCD)factorization approach. we find the following results: (a) if the scalar meson $f_0(980)$ is viewed as a mixture of $s\bar s$ and $(u\bar u+d\bar d)/\sqrt{2}$, the branching ratios of the decays $\bar{B}^0\to f_0(980)\rho^0(\omega,\phi)$ and $B^-\to f_0(980)\rho^-$, which are induced by $b\to d$ transition, are smaller than the currently experimental upper limits, and the predictions for the decay $\bar{B}^0\to f_0(980)\omega, B^-\to f_0(980)\rho^-$ are not far away from their limits; (b) in the decays $B\to K^*_0(1430)\rho(\omega)$, which are induced by $b\to s$ transition, the branch ratio of $\bar B^0\to K^{*0}_0(1430)\rho^0$ is the smallest one in two scenarios, at the order of $10^{-7}$ for scenario I, about $4.8\times10^{-6}$ for scenario II; (c) the direct CP-asymmetries of the decays $B\to f_0(980)\rho(\omega)$ have a strong dependent on the mixing angle $\theta$: they are large in the range of $25^\circ<\theta<40^\circ$, and small in the range of $140^\circ<\theta<165^\circ$, while the direct CP-asymmetries of the decays $B\to K^{*}_0(1430)\rho(\omega)$ are not large in both scenarios and most of them are less than 20% in size.