  We show that deformed relativistic kinematics, expected to emerge in a
flat-spacetime limit of quantum gravity, predicts different lifetimes for
particles and their antiparticles. This phenomenon is a consequence of
Planck-scale modifications of the action of discrete symmetries. In particular
we focus on deformations of the action of CPT derived from the kappa-Poincare
algebra, the most studied example of Planck-scale deformation of relativistic
symmetries. Looking at lifetimes of muons and anti-muons we are able to derive
an experimental bound on the deformation parameter of kappa > 4x10^14 GeV from
measurements at the LHC. Such bound has the potential to reach the value of
kappa > 2x10^16 GeV using measurements at the planned Future Circular Collider
(FCC).
