$\hat{I}{›}_{\mathrm{c}}^{+}$ polarimetry using the dominant hadronic mode

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 $\hat{I}{›}_{\mathrm{c}}^{+}\to p{K}^{-}\ddot{I}{€}^{+}$ 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 $\hat{I}{›}_{\mathrm{c}}^{+}$ baryon and eases inclusion of the $\hat{I}{›}_{\mathrm{c}}^{+}\to p{K}^{-}\ddot{I}{€}^{+}$ decay mode in hadronic amplitude analyses.

All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-044.html (LHCb public pages)