Violation of the Landau-Yang theorem from infrared Lorentz symmetry breaking

Abstract

Lorentz symmetry forbids decays of massive spin-1 particle like the Z0 into two massless photons, a result known as the Landau-Yang theorem. But it is known that infrared effects can break Lorentz invariance. Employing the construction of Mund et al. [1] which incorporated this Lorentz violation, we propose an interaction leading to the decay Z0→ 2γ and study the dependence of the decay on the parameter of this Lorentz violation.