Amplitude analysis of $$B^0 \rightarrow \eta _c(1S) K^+ \pi ^- $$ decays

Abstract An amplitude analysis of the $${{{B} ^0} \!\rightarrow {\eta _{c}} (1S) {{K} ^+} {{\pi } ^-}} $$ B 0 → η c ( 1 S ) K + π - decays with $${\eta _{c}} (1S) \rightarrow {p} {\overline{{p}}} $$ η c ( 1 S ) → p p ¯ is performed using a sample corresponding to an integrated luminosity of 9 $$\,\text {fb} ^{-1}$$ fb - 1 of $$p $$ p $$p $$ p collision data collected by the LHCb detector at centre-of-mass energies of $$\sqrt{s}$$ s = 7, 8 and 13 $$\,\text {Te\hspace{-1.00006pt}V}$$ Te V . The data are described with a model including only intermediate contributions from known $${K} ^{*0}$$ K ∗ 0 resonances. Evidence for an exotic resonance in the $${\eta _{c}} (1S) {{\pi } ^-} $$ η c ( 1 S ) π - system, reported in a previous analysis of this decay channel, is not confirmed. The inclusive branching fraction of the $${{B} ^0} \rightarrow {\eta _{c}} (1S) {{K} ^+} {{\pi } ^-} $$ B 0 → η c ( 1 S ) K + π