Amplitude Analysis of the $$ {\lambda}_{\textrm{b}}^0\to {\Textrm{pk}}^{-}\Upgamma $$ Decay

A bstract The resonant structure of the radiative decay $$ {\Lambda}_b^0\to {pK}^{-}\gamma $$ Λ b 0 → pK − γ in the region of proton-kaon invariant-mass up to 2.5 GeV/ c 2 is studied using proton-proton collision data recorded at centre-of-mass energies of 7, 8, and 13 TeV collected with the LHCb detector, corresponding to a total integrated luminosity of 9 fb − 1 . Results are given in terms of fit and interference fractions between the different components contributing to this final state. Only Λ resonances decaying to pK − are found to be relevant, where the largest contributions stem from the Λ(1520), Λ(1600), Λ(1800), and Λ(1890) states.