Related papers: A Bound on Violations of Lorentz Invariance
A hypothetical violation of Lorentz invariance in the electrons' equation of motion (expressed within the Lorentz-violating extension of the standard model) leads to a change of the geometry of crystals and thus shifts the resonance…
We propose a simple model of spontaneous lepton number violation with potentially large flavor violating decays, including the possibility that majoron emitting decays, such as $\mu \to e \, J$, saturate the experimental bounds. In this…
Cosmic rays have extremely high particle energies (up to $10^{20} \; \text{eV}$) and can be used to search for violations of Lorentz invariance. We consider isotropic nonbirefringent Lorentz violation in the photon sector for the case of a…
Any theory that have a global spontaneously broken symmetry will imply the existence of very light neutral bosons or massless bosons (sometimes called Majorons). For most of these models we have neutrino-Majoron couplings, that appear as…
We present a new result based on an analysis of the data collected by the MEG detector at the Paul Scherrer Institut in 2009 and 2010, in search of the lepton flavour violating decay mu->e gamma. The likelihood analysis of the combined data…
The lepton flavor violating decay of the Higgs boson $H\to l_Al_B$ is studied within two qualitatively different extensions of the Yukawa sector: one renormalizable and the other nonrenormalizable; both incorporating Lorentz violation in a…
Lorentz invariance is a fundamental symmetry of spacetime underpinning the Standard Model (SM) and our understanding of high-energy phenomena in particle physics. However, beyond the quantum gravity scale, we expect the SM to be replaced…
A clock comparison experiment, analyzing the ratio of spin precession frequencies of stored ultracold neutrons and $^{199}$Hg atoms is reported. %57 No daily variation of this ratio could be found, from which is set an upper limit on the…
In this paper we study the Lepton Flavor Violating $Z$ boson decays $Z \to \tau \mu$ and $Z \to \tau e$ in the context of low scale seesaw models with new heavy Majorana neutrinos whose masses could be reachable at the LHC. Our computations…
In quantum theory of gravity, we expect the Lorentz Invariance Violation (LIV) and the modification of the dispersion relation between energy and momentum for photons. The effect of the energy-dependent velocity due to the modified…
Within the model of a Lorentz violating extension of the Maxwell sector of the standard model, modified light propagation leads to a change of the resonance frequency of an electromagnetic cavity, allowing cavity tests of Lorentz violation.…
Possible violations of Lorentz invariance (LIV) can produce vacuum birefringence, which results in a frequency-dependent rotation of the polarization plane of linearly polarized light from distant sources. In this paper, we try to search…
The relation between the violation of Lorentz invariance and the dynamical effects in high energy gamma rays production is discussed. By using the framework of noncommutative classical electrodynamics, it is shown that full dynamical…
Breaking of isotropy and Lorentz boost invariance in the dynamics of second-generation leptons would lead to direction-dependent changes in the lifetimes of charged pions. This would make the intensity of a neutrino beam produced via pion…
The notion that gravitation might lead to a breakdown of standard space-time structure at small distances, and that this might affect the propagation of ordinary particles has led to a program to search for violations of Lorentz invariance…
We derive new bounds on Lorentz violations in the electron sector from existing data on high-energy astrophysical sources. Synchrotron and inverse Compton data give precisely complementary constraints. The best bound on a specific…
Lorentz invariance is a cornerstone of modern physics, yet its possible violation remains both theoretically intriguing and experimentally significant. In this work, using quantum electrodynamics as an example, we explore how Lorentz…
In light of the increasing hints of new physics at the muon $g-2$ and neutrino oscillation experiments, we consider the recently observed tension in the long-baseline neutrino oscillation experiments as a potential indication of Lorentz…
Upon a suggestion of Kostelecky et al., we have performed a test of CPT and Lorentz invariance from the microwave spectroscopy of muonium. New terms in their standard model extension violating CPT and Lorentz symmetry would appear as…
We present a method for constraining Lorentz violation in the electron sector, based on observations of the photons emitted by high-energy astrophysical sources. The most important Lorentz-violating operators at the relevant energies are…