Abstract
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 \( {\Lambda}_c^{+} \) → 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 \( {\Lambda}_c^{+} \) baryon and eases inclusion of the \( {\Lambda}_c^{+} \) → pK−π+ decay mode in hadronic amplitude analyses.
