Abstract

We present a detailed study of charmless two-body B decays into final states involving two vector mesons (VV) or two axial-vector mesons (AA) or one vector and one axial-vector meson (VA), within the framework of QCD factorization, where $A$ is either a $^3P_1$ or $^1P_1$ axial-vector meson. The main results are as follows. (i) In the presence of NLO nonfactorizable corrections, effective Wilson coefficients $a_i^h$ are helicity dependent. For some penguin-dominated modes, the constructive (destructive) interference in the negative-helicity (longitudinal-helicity) amplitude of the $B\to VV$ decay will render the former comparable to the latter and push up the transverse polarization. (ii) In QCD factorization, the transverse polarization fraction can be large for penguin-dominated charmless $VV$ modes by allowing for sizable penguin annihilation contributions. (iii) Using the measured $\bar K^{*0}\rho^-$ channel as an input, we predict the branching ratios and polarization fractions for other $\ov B\to \bar K^*\rho$ decays. (iv) The smallness of the axial-vector decay constant of the $^1P_1$ axial vector meson can be tested by measuring various $b_1\rho$ modes to see if $\Gamma(\bar B^0\to b_1^-\rho^+)\ll \Gamma(\bar B^0\to b_1^+\rho^-)$ and $\Gamma(B^-\to b_1^-\rho^0)\ll \Gamma(B^-\to b_1^0\rho^-)$. (v) For the penguin-dominated modes $a_1K^*$ and $b_1K^*$, it is found that the former are dominated by transverse polarization amplitudes, whereas the latter are governed by longitudinal polarization states.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call