Threshold anomalies in Horava-Lifshitz-type theories

Understand

Recently the study of threshold kinematic requirements for particle-production processes has played a very significant role in the phenomenology of theories with departures from Poincare' symmetry.

• We here specialize these threshold studies to the case of a class of violations of Poincare' symmetry which has been much discussed in the literature on Horava-Lifshitz scenarios.
• These involve modifications of the energy-momentum ("dispersion") relation that may be different for different types of particles, but always involve even powers of energy-momentum in the correction terms.
• We establish the requirements for compatibility with the observed cosmic-ray spectrum, which is sensitive to the photopion-production threshold.