Nonleptonic two-body B-decays including axial-vector mesons in the final state

TL;DR

This paper systematically analyzes charmless nonleptonic two-body B decays involving axial-vector mesons, calculating branching ratios using factorization and improved quark models, and exploring decay dependencies on mixing angles.

Contribution

It provides the first detailed calculation of branching ratios for B decays to axial-vector mesons using an improved nonrelativistic quark model and factorization, including penguin contributions.

Findings

Certain B decay modes have branching ratios around 10^{-5}.

Branching ratios depend on the mixing angle between K1(1270) and K1(1400).

The study offers predictions useful for experimental verification.

Abstract

We present a systematic study of exclusive charmless nonleptonic two-body B decays including axial-vector mesons in the final state. We calculate branching ratios of B\to PA, VA and AA decays, where A, V and P denote an axial-vector, a vector and a pseudoscalar meson, respectively. We assume naive factorization hypothesis and use the improved version of the nonrelativistic ISGW quark model for form factors in B\to A transitions. We include contributions that arise from the effective \Delta B=1 weak Hamiltonian H_{eff}. The respective factorized amplitude of these decays are explicitly showed and their penguin contributions are classified. We find that decays B^-to a_1^0\pi^-,\barB^0\to a_1^{\pm}\pi^{\mp}, B^-\to a_1^-\bar K^0, \bar B^0\to a_1^+K^-, \bar B^0\to f_1\bar K^0, B^-\to f_1K^-, B^-\to K_1^-(1400)\etap, B^-\to b_1^-\bar K^{0}, and \bar B^0\to b_1^+\pi^-(K^-) have branching ratios of the order of 10^{-5}. We also study the dependence of branching ratios for B \to K_1P(V,A) decays (K_1=K_1(1270),K_1(1400)) with respect to the mixing angle between K_A and K_B.