Λc+​ polarimetry using the dominant hadronic mode

The polarimeter vector field for multibody decays of a spin-half baryon is introduced as a generalisation of the baryon asymmetry parameters. Using a recent amplitude analysis of the Λc+​ → pK−π+ decay performed at the LHCb experiment, we compute the distribution of the kinematic-dependent polarimeter vector for this process in the space of Mandelstam variables to express the polarised decay rate in a model-agnostic form. The obtained representation can facilitate polarisation measurements of the Λc+​ baryon and eases inclusion of the Λc+​→ pK−π+ decay mode in hadronic amplitude analyses. [graphic not available: see fulltext]