Amplitude analysis of the B(s)0→K∗0 K¯∗0 decays and measurement of the branching fraction of the B→ K∗ 0K¯ ∗ 0 decay

Abstract

The B→ KK¯ and Bs0→K∗0K¯∗0 decays are studied using proton-proton collision data corresponding to an integrated luminosity of 3 fb. An untagged and timeintegrated amplitude analysis of B → (Kπ)(Kπ) decays in two-body invariant mass regions of 150 MeV/c around the K mass is performed. A stronger longitudinal polarisation fraction in the B→ KK¯ decay, f = 0.724 ± 0.051 (stat) ± 0.016 (syst), is observed as compared to f = 0.240 ± 0.031 (stat) ± 0.025 (syst) in the Bs0→K∗0K¯∗0 decay. The ratio of branching fractions of the two decays is measured and used to determine ℬ(B0→K∗0K¯∗0)=(8.0±0.9(stat)±0.4(syst))×10−7.[Figure not available: see fulltext.]