Related papers: Bounds on Cubic Lorentz-Violating Terms in the Fer…
We investigate the breaking of Lorentz symmetry caused by the inclusion of an external four-vector via a Chern-Simons-like term in the Duffin-Kemmer-Petiau Lagrangian for massless and massive spin-one fields. The resulting equations of…
The prospects are explored for testing Lorentz and CPT symmetry in the muon sector via the spectroscopy of muonium and various muonic atoms, and via measurements of the anomalous magnetic moments of the muon and antimuon. The effects of…
Inspired in discussions presented lately regarding Lorentz-violating interaction terms in \cite{13,6}, we propose here a slightly different version for the coupling term. We will consider a modified quantum electrodynamics with violation of…
The influence of Lorentz- and CPT-violating terms (in "vector" and "axial vector" couplings) on the Dirac equation is explicitly analyzed: plane wave solutions, dispersion relations and eigenenergies are explicitly obtained. The…
The breaking of Lorentz symmetry via a dynamical mechanism, with a tensor field which takes on a non-zero expectation value in vacuum, has been a subject of significant research activity in recent years. In certain models of this type, the…
Possible signals for indirect CPT violation arising in experiments with neutral kaons are considered in the context of a general CPT- and Lorentz-violating standard-model extension. Certain CPT observables can depend on the meson momentum…
We study an extension of QED involving a light pseudoscalar (an axion-like particle), together with a very massive fermion which has Lorentz-violating interactions with the photon and the pseudoscalar, including a nonminimal…
In this work we derive the Lorentz-PCT-violating effective action for a fermion in a constant and uniform electromagnetic field using the Fock-Schwinger proper time method and extract the exact value of the coefficient of the…
Forbidden (slow) beta decays offer new opportunities to test the invariance of the weak interaction under Lorentz transformations. Within a general effective field theory framework we analyze and reinterpret the only two relevant…
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…
We study CPT and Lorentz violation in the electroweak gauge sector of the Standard Model in the context of the Standard-Model Extension. In particular, we consider the Lorentz-violating and CPT-odd Chern-Simons like parameter for the W…
The smallness and hierarchy of the fermion parameters could be explained in theories with extra dimensions where doublets and singlets are localized at slightly separated points. Scattering cross sections for collisions of such fermions…
A parton-model description of high-energy hadronic interactions in the presence of Lorentz violation is presented. This approach is used to study lepton-hadron and hadron-hadron interactions at large momentum transfer. Cross sections for…
Direct laboratory bounds on the 9 nonbirefringent Lorentz-violating dimensionless parameters of modified-Maxwell theory range from the 10^{-7} level to the 10^{-16} level. The detection of air showers initiated by charged primaries…
In this work, we propose two possibilities of CPT-odd and Lorentz-violating (LV) nonminimal couplings in the Electroweak sector. These terms are gauge-invariant and couple a fixed 4-vector to the physical fields of the theory. After…
We study the perturbative generation of higher-derivative operators as corrections to the photon effective action, which are originated from a Lorentz violation background. Such corrections are obtained, at one-loop order, through the…
Geometric phases can manifest when a relativistic quantum particle moves cyclically along a loop in parameter space. The phase can be affected by the presence of a background field and can be accompanied by nontrivial topological features.…
Sensitive tests of Lorentz invariance can emerge from the study of neutrino oscillations, particularly for atmospheric neutrinos where the effect is conveniently near-maximal and has been observed over a wide range of energies. We assume…
Colladay and Kostelecky have proposed a framework for studying Lorentz and CPT violation in a natural extension of the Standard Model. Although numerous bounds exist on the Lorentz and CPT violating parameters in the gauge boson and fermion…
Charged-pion decay offers many opportunities to study Lorentz violation. Using an effective field theory approach, we study Lorentz violation in the lepton, W-boson, and quark sectors and derive the differential pion-decay rate, including…