Hadronic Lorentz violation in chiral perturbation theory

Lorentz violation in hadronic systems is related to Lorentz-violating operators of quarks and gluons. Due to the nonperturbative nature of quantum chromodynamics (QCD) at low energies, establishing these relationships is complex. Chiral perturbation theory (ChPT) is an effective theory that provides one method of connecting quark- and gluon-level operators to those at the hadronic level, which can be used to calculate hadronic observables.