Nonleptonic decays of $B o ( f_1(1285),f_1(1420) ) V$ in the perturbative QCD approach

摘要

We investigate the branching ratios, the polarization fractions, the directCP-violating asymmetries, and the relative phases in 20 nonleptonic decay modesof $B \to f_1 V$ within the framework of perturbative QCD approach at leadingorder with $f_1$ including two $^3\!P_1$-axial-vector states $f_1(1285)$ and$f_1(1420)$. Here, $B$ denotes $B^+$, $B^0$, and $B_s^0$ mesons and $V$ standsfor the lightest vector mesons $\rho$, $K^*$, $\omega$, and $\phi$ ,respectively. The $B_s^0 \to f_1 V$ decays are studied theoretically for thefirst time in the literature. Together with the angle $\phi_{f_1} \approx(24^{+3.2}_{-2.7})^\circ$ extracted from the measurement through $B_{d/s} \toJ/\psi f_1(1285)$ modes for the $f_1(1285)-f_1(1420)$ mixing system, it is ofgreat interest to find phenomenologically some modes such as the tree-dominated$B^+ \to f_1 \rho^+$ and the penguin-dominated $B^{+,0} \to f_1 K^{*+,0}, B_s^0\to f_1 \phi$ with large branching ratios around ${\cal O}(10^{-6})$ or even${\cal O}(10^{-5})$, which are expected measurable at the LHCb and/or theBelle-II experiments in the near future. The good agreement [sharp contrast] ofbranching ratios and decay pattern for $B^+ \to f_1 \rho^+, B^{+,0} \tof_1(1285) K^{*+,0} [B^{+,0} \to f_1(1420) K^{*+,0}]$ decays between QCDfactorization and perturbative QCD factorization predictions can help us todistinguish these two rather different factorization approaches via precisionmeasurements, which would also be helpful for us to explore the annihilationdecay mechanism through its important roles for the considered $B \to f_1 V$decays.