Amplitude analysis of B0 → ηc(1S)K +π− decays

An amplitude analysis of the B0 → ηc(1S)K +π−decays with ηc(1S) → p p is performed using a sample corresponding to an integrated luminosity of 9 fb−1 of p p collision data collected by the LHCb detector at centre-of-mass energies of √s = 7, 8 and 13 TeV. The data are described with a model including only intermediate contributions from
known K ∗0 resonances. Evidence for an exotic resonance in the ηc(1S)π− system, reported in a previous analysis of this decay channel, is not confirmed. The inclusive branching fraction of the B0 → ηc(1S)K +π− decays is measured to be B(B0 → ηc(1S)K +π−)= (5.82 ± 0.20 ± 0.23 ± 0.55) × 10−4, where the first uncertainty is statistical, the second systematic, and the third arises from the limited knowledge of external branching fractions.