Charmless B decays to a scalar meson and a vector meson

Abstract

The hadronic charmless B decays into a scalar meson and a vector meson are studied within the framework of QCD factorization. The main results are: (i) The decay rates for the $f_0(980)K^{\ast -}$ and $f_0(980)\ov K^{*0}$ modes depend on the $f_0-\sigma$ mixing angle $\theta$. The experimental measurements can be accommodated for $\theta \approx 20^{\circ }$. (ii) If the $a_0(980)$ is a $q\bar{q}$ bound state, the predicted branching ratios for the channels $a_0^{+}{\rho }^{-}$ and $a_0^0{\rho }^{-}$ will be very large, of order $30\times 10^{-6}$ and $23\times 10^{-6}$, respectively. If the observation of or the experimental limit on theses two modes is much smaller than the expectation of $\sim 25\times 10^{-6}$, this could hint at a four-quark nature for the $a_0(980)$. (iii) For the $a_0(1450)$ channels, $a_0^{+}(1450){\rho }^{-}$ and $a_0^0(1450){\rho }^{-}$ are found to have branching ratios of order $16\times 10^{-6}$ and $22\times 10^{-6}$, respectively. A measurement of them at the predicted level will favor the $q\bar{q}$ structure for the $a_0(1450)$. (iv) Contrary to the naive expectation that $\Gamma (B^{-}\to a_0^0{\rho }^{-})\sim \frac{1}{2}\Gamma ({\bar{B}}^0\to a_0^{+}{\rho }^{-})$, we found that they have comparable rates due to additional contributions to the $a_0{\rho }^{-}$ mode from the $a_0^0$ emission. (v) The predicted central value of $Br(\bar B^0\to\ov K^{*0}_0(1430)ϕ)$ is larger than experiment, though it can be accommodated within theoretical errors. The decays $B\to K_0^{\ast }(1430)\rho$ are expected to have rates substantially larger than that of $B\to K_0^{\ast }(1430)\pi$ owing to the constructive (destructive) interference between the $a_4$ and $a_6$ penguin terms in the former (latter). Experimentally, it is thus important to check if the $B\to K_0^{\ast }\rho$ modes are enhanced relative to the corresponding $K_0^{\ast }\pi$ channels.

21 pages, 1 figure

References in corpus (7)

• Branching fractions, polarisation and asymmetries of B -> VV decays
• B->V gamma Beyond QCD Factorisation
• Charmless Three-body Decays of B Mesons
• Scalar Mesons a0(1450) and sigma(600) from Lattice QCD
• Study of scalar mesons f_0(980) and f_0(1500) from $B\to f_0(980)K$ and $B\to f_0(1500)K$ Decays
• Study of $K_0^{\ast }(1430)$ and $a_0(980)$ from $B\to K_0^{\ast }(1430)\pi$ and $B\to a_0(980)K$ Decays
• Expectations on $B\to (K_0^{\ast }(1430),K_2^{\ast }(1430))\varphi$ decays

Cited by in corpus (5)

• Hadronic D decays involving even-parity light mesons
• Study of scalar meson a_0(1450) from B \to a_0(1450)K^* Decays
• Branching Ratio and CP Asymmetry of B_s \to K^*_0(1430)ρ(ω,ϕ) Decays in the PQCD Approach
• Study of f_0(980) and f_0(1500) from B_s \to f_0(980)π, f_0(1500)πDecays
• Instanton effects on the twist-three light-cone distribution amplitudes of pion and light scalar mesons above 1GeV