Observation of $B^0_s \to K^{*\pm}K^\mp$ and evidence for $B^0_s \to K^{*-}\pi^+$ decays

Abstract

Measurements of the branching fractions of B0 s → K∗±K∓ and B0 s → K∗±π ∓ decays are performed using a data sample corresponding to 1.0 fb−1 of protonproton collision data collected with the LHCb detector at a centre-of-mass energy of 7 TeV, where the K∗± mesons are reconstructed in the K0 S π ± final state. The first observation of the B0 s → K∗±K∓ decay and the first evidence for the B0 s → K∗−π + decay are reported with branching fractions B B 0 s → K∗±K∓ = (12.7 ± 1.9 ± 1.9) × 10−6 , B B 0 s → K∗−π + = (3.3 ± 1.1 ± 0.5) × 10−6 , where the first uncertainties are statistical and the second are systematic. In addition, an upper limit of B B0→ K∗±K∓ < 0.4 (0.5)×10−6 is set at 90 % (95 %) confidence lev