Hadronic Lorentz Violation in Chiral Perturbation Theory

Understand

Any possible Lorentz violation in the hadron sector must be tied to Lorentz violation at the underlying quark level.

• The relationships between the theories at these two levels are studied using chiral perturbation theory.
• Starting from a two-flavor quark theory that includes dimension-four Lorentz-violation operators, the effective Lagrangians are derived for both pions and nucleons, with novel terms appearing in both sectors.
• Since the Lorentz violation coefficients for nucleons and pions are all related to a single set of underlying quark coefficients, it is possible to place approximate bounds on pion Lorentz violation using only proton and neutron observations.