Astrophysical limits on Lorentz violation for all charged species

Abstract

If Lorentz violation exists, it will affect the thresholds for pair creation processes. Lorentz-violating operators that change the maximum velocities of charged particles may increase or decrease the extinction rate of γ-rays moving through space. If the emissions from high-energy astrophysical sources do not show any signs of anomalous absorption, this allows us to place bounds on the Lorentz-violating c coefficients for multiple species of charged particles. The bounds for a species of mass m X based on observing photons at an energy E γ can be O(m

Asymptotic states and renormalization in Lorentz-violating quantum field theory

“…Third, we also note that various experimental investigations have sought to constrain 2c µν −k µν . In particular, measurements have been performed in the context of resonance cavities [35], kinematical threshold studies at colliders [26], synchrotron radiation [27], Compton-edge investigations in electron-photon scattering [28], and astrophysical observations [36]. Through these investigations, all components of 2c µν −k µν are currently obeying bounds at the levels of 10 −13 .…”

“…However, by virtue of Eq. (36) we see that (P 2 + 2mP ) = p 2 −β is proportional to 1 1 and thus commutes with any matrix. Therefore, we may write for n ≥ 2,…”

Laboratory tests of Lorentz andCPTsymmetry with muons

“…The latter have also been used to place limits on nonminimal interaction terms with d ¼ 5 [13], while minimal-SME interactions have been studied in the context of muon decay [14]. A few constraints from astrophysical processes have been obtained as well, both for minimal-SME coefficients [15] and for isotropic nonminimal operators with d ¼ 5, 6 [16,17].…”

Neutrino beam constraints on flavor-diagonal Lorentz violation

“…It is also poorer than the ∼ 10 −11 sensitivity that has been obtained from the observed absence of the photon decay reaction γ → µ − + µ + for cosmic ray photons [73]; however, because the photon is a spin-1 state, the daughter particles in such a reaction would necessarily have parallel spins, which makes such constraints only sensitive to the spin-averaged c coefficients, rather than the left-chiral c L . On the other hand, the sensitivity of the new method discussed in this paper is comparable to that achieved for flavor-diagonal effects using direct time-of-flight measurements, and this new strategy can represent an important tool for constraining boost and isotropy violation in the difficult-to-access neutrino sector.…”