Representation and Estimation of Trajectories from Two-body Decays

A novel parametrization of the trajectories stemming from two-body decays is presented, based on the kinematics of the decay. The core component of this parametrization is a decay model which is derived using the relativistic energy-momentum conservation law and geometrical fundamentals. The estimation of the decay parameters, also including the beam profile and a mass constraint, is described. Some applications in realistics scenarios are presented. In addition, the representation of the trajectories for the use in track-based alignment algorithms is briefly discussed.