Violation of Lorentz invariance and neutral component of UHECR

The observed clustering of ultra-high energy cosmic rays suggests the existence of a neutral component. The models with violation of Lorentz invariance may explain this component by neutrons becoming stable above some threshold energy E0. The protons, in turn, may become unstable above some energy E1>E0. We calculate the dependence of the threshold energies E0 and E1 on the parameters of the model and find E1/E0≳1.5. We argue that the characteristic threshold behavior of charged and neutral components may be used as the specific signature of models with violation of Lorentz invariance. The existence of the neutron stability threshold E0 can be investigated with already existing data.