Proposal for particle-level object and observable definitions for use in physics measurements at the LHC

Measurements and theory predictions at the proton-proton collider LHC become increasingly precise. This makes it necessary to use definitions in the physics measurements that allow for a meaningful comparison of theory and experiment. Moreover, measurements should be defined such that they have a minimal model dependence and that future Monte Carlo simulation can be used for data comparisons. A suitable measurement definition can be based on the stable particles entering the detector. In this note a proposal for the definition of truth particles in the Monte Carlo simulation and observables derived from them is discussed.