Study of the pure annihilation Bc→A2A3 decays

In this work, we calculate the CP-averaged branching ratios and the polarization fractions of the charmless hadronic Bc→A2A3 decays within the framework of perturbative QCD (pQCD) approach, where A is either a light 3P1 or 1P1 axial-vector meson. These 32 decay modes can occur through the annihilation topology only. Based on the perturbative calculations and phenomenological analysis, we find the following results: (a) the branching ratios of the considered 32 Bc→A2A3 decays are in the range of 10-5 to 10-8; (b) Bc→a1b1, K10K1+ and some other decays have sizable branching ratios and can be measured at the LHC experiments; (c) the branching ratios of Bc→A2(1P1)A3(1P1) decays are generally much larger than those of Bc→A2(3P1)A3(3P1) decays with a factor around (10∼100); (d) the branching ratios of Bc→K10K1+ decays are sensitive to the value of θK, which will be tested by the running LHC and forthcoming SuperB experiments; (e) the large longitudinal polarization contributions govern most considered decays and play the dominant role.