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

TL;DR

This paper studies nonleptonic B meson decays to axial-vector and vector mesons using perturbative QCD, providing predictions for branching ratios, polarization, and CP asymmetries, including first theoretical analysis of certain B_s decays.

Contribution

It offers the first theoretical analysis of B_s^0  f_1 V decays and compares QCD factorization with perturbative QCD predictions for these processes.

Findings

Predicted large branching ratios for certain decay modes (~10^{-6} to 10^{-5})

Good agreement between QCD and pQCD for some decay patterns

Identification of decay modes suitable for measurement at LHCb and Belle-II

Abstract

We investigate the branching ratios, the polarization fractions, the direct CP-violating asymmetries, and the relative phases in 20 nonleptonic decay modes of $B \to f_1 V$ within the framework of perturbative QCD approach at leading order 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 $V$ stands for the lightest vector mesons $\rho$, $K^*$, $\omega$, and $\phi$ , respectively. The $B_s^0 \to f_1 V$ decays are studied theoretically for the first time in the literature. Together with the angle $\phi_{f_1} \approx (24^{+3.2}_{-2.7})^\circ$ extracted from the measurement through $B_{d/s} \to J/\psi f_1(1285)$ modes for the $f_1(1285)-f_1(1420)$ mixing system, it is of great 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 the Belle-II experiments in the near future. The good agreement [sharp contrast] of branching ratios and decay pattern for $B^+ \to f_1 \rho^+, B^{+,0} \to f_1(1285) K^{*+,0} [B^{+,0} \to f_1(1420) K^{*+,0}]$ decays between QCD factorization and perturbative QCD factorization predictions can help us to distinguish these two rather different factorization approaches via precision measurements, which would also be helpful for us to explore the annihilation decay mechanism through its important roles for the considered $B \to f_1 V$ decays.