Related papers: Radiative corrections and Lorentz violation
Constraints on the birefringence-free subset of Lorentz-violating (LV) operators are derived using 14 GRB photons in the GeV-band. These constraints target the isotropic $c_{(I)00}^{(d)}$ coefficients for dimensions $d=6,8,10$ within the…
We consider an extended QED with the addition of a dimension-five Lorentz-breaking coupling between spinor and gauge fields, involving a pseudo-tensor $\kappa^{\mu\nu\lambda\rho}$. The specific form of the Lorentz violating coupling…
We provide the first step towards renormalization in a nonminimal Lorentz-violating model consisting of normal scalars and modified fermions with mass dimension five operators. We compute the radiative corrections corresponding to the…
Lorentz violation (LV) is predicted by some quantum gravity theories, where photon dispersion relation is modified, and the speed of light becomes energy-dependent. Consequently, it results in a tiny time delay between high energy photons…
We have performed a complete study of BPS vortex solutions in the Abelian sector of the standard model extension (SME). Specifically, we have coupled the SME electromagnetism with a Higgs field which is supplemented with a Lorentz-violating…
We look for modifications that can be derived from the Maxwell sector of the SME for the interaction between electrical charges and the electromagnetic field. The kind of problem that we are looking into is the one that might be found in a…
Lepton number violating (LNV) $A(e^-,e^+)X$ double charge exchange (LDCE) reactions on nuclei at accelerator facilities with multi-GeV beams are proposed as a probe for physics beyond the Standard Model (BSM). A second order formalism is…
This paper presents divergent contributions of the radiative corrections for a Lorentz-violating extension of the scalar electrodynamics. We initially discuss some features of the model and extract the Feynman rules. Then we compute the…
We present constraints on violations of Lorentz Invariance based on Lunar Laser Ranging (LLR) data. LLR measures the Earth-Moon separation by timing the round-trip travel of light between the two bodies, and is currently accurate to a few…
Lorentz Violation (LV) is posited as a possible relic effect of quantum gravity at low energy scales. The Standard-Model Extension provides an effective field-theoretic framework for examining possible deviations attributed to LV. With…
Spacetime nonmetricity can be studied experimentally through its couplings to fermions and photons. We use recent high-precision searches for Lorentz violation to deduce first constraints involving the 40 independent nonmetricity components…
The modified Dirac equation in the Lorentz-violating Standard-Model Extension (SME) is considered. Within this framework, the construction of a hermitian Hamiltonian to all orders in the Lorentz-breaking parameters is investigated, discrete…
If physics at the Planck scale requires new conceptions of space-time, then generic renormalizable field theories predict observable violations of Lorentz invariance in the low energy sector. The little recognized ``Lorentz Fine Tuning…
A more complete theoretical model of testing Lorentz violation by the comparison of atomic clocks is developed in the Robertson-Mansouri-Sexl kinematic framework. As this frame postulates the deviation of the coordinate transformation from…
This paper explores some propagation features of electrodynamics in a Lorentz-violating scenario, focusing on a specific CPT-even term within the photon sector of the Standard Model Extension (SME). The study derives a covariant dispersion…
In recent years, exciting (indirect) hints for physics beyond the Standard Model (SM) have been accumulated. In particular, semi-leptonic $B$ decays show deviations from the SM predictions, which, due to the ratios $R(K^{(*)})$ and…
In a new theory, local Lorentz invariance is a low-energy symmetry which no longer holds when a fermion energy E is well above 1 TeV. Here we find that the modified E(p) relation is consistent with observation, and is in fact nearly the…
If violation of Lorentz and CPT symmetry is introduced into the fermion sector of conventional quantum electrodynamics, then the Chern-Simons term is radiatively induced with finite nonzero coefficient, as well as the Maxwell term is with…
Some motivations for Lorentz-symmetry tests in the context of quantum-gravity phenomenology are reiterated. The description of the emergent low-energy effects with the Standard-Model Extension (SME) is reviewed. The possibility of…
We investigate the relativistic dynamics of a spin half particle in the presence of a Lorentz-violating background within the framework of effective field theory. A modified Dirac Hamiltonian is considered, arising from a CPT odd coupling…