paper

Amplitude analysis of decays

arXiv:2509.03133 · doi:10.1140/epjc/s10052-026-15474-w

Abstract

An amplitude analysis of the decays with is performed using a sample corresponding to an integrated luminosity of 9 of collision data collected by the LHCb detector at centre-of-mass energies of = 7, 8 and 13TeV. The data are described with a model including only intermediate contributions from known resonances. Evidence for an exotic resonance in the system, reported in a previous analysis of this decay channel, is not confirmed. The inclusive branching fraction of the decays is measured to be \begin{align*} \mathcal{B}(B^0 \rightarrow η_{c}(1S) K^+ π^- ) = (5.82 \pm 0.20 \pm 0.23 \pm 0.55) \times 10^{-4}, \end{align*} where the first uncertainty is statistical, the second systematic, and the third arises from the limited knowledge of external branching fractions.

All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://lbfence.cern.ch/alcm/public/analysis/full-details/4255/ (LHCb public pages)