Related papers: Low Energy Tests of Lorentz and CPT Violation
A status report is given of some recent theoretical and experimental investigations looking for signals of Lorentz violation in QED. Experiments with light, charged particles, and atoms have exceptional sensitivity to small shifts in energy…
In the context of conventional quantum field theory, we present a general Lorentz-violating extension of the minimal SU(3) x SU(2) x U(1) standard model including CPT-even and CPT-odd terms. It can be viewed as the low-energy limit of a…
A popular framework for exploring Lorentz violation is the Standard Model Extension. This extension contains a large number of parameters that can be bounded in various experiments. Most studies, however, focus on the fermion or photon…
The Standard-Model Extension (SME) provides a comprehensive effective field-theory framework for the study of CPT and Lorentz symmetry. This work reviews the structure and philosophy of the SME and provides some intuitive examples of…
The Standard-Model Extension (SME) provides a theoretical framework for tests of Lorentz invariance. To date, most studies have focused on the minimal SME, which restricts attention to operators of renormalizable dimension. Here, we review…
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 have studied the effect of hypothetical violations of Lorentz and CPT symmetry by calculating the corrections to the energy levels of hydrogen induced by the Standard-Model Extension (SME). Hydrogen studies are interesting because the…
CPT and Lorentz violation in the photon sector is described within the minimal Standard-Model Extension by a dimension-3 Chern-Simons-like operator parametrized by a four-vector parameter $k_{AF}$ that has been very tightly bounded by…
We present in this work an analysis of Lorentz- and CPT-violating signals at linear boost order in Penning-trap experiments. The theory of quantum electrodynamics with Penning traps is revisited and the dominant shifts in the cyclotron and…
Stability and causality are investigated for quantum field theories incorporating Lorentz and CPT violation. Explicit calculations in the quadratic sector of a general renormalizable lagrangian for a massive fermion reveal that no…
This work presents a model for testing Lorentz and CPT symmetry through sidereal-variation studies of the hyperfine-Zeeman deuterium ground-state transition frequencies. It represents an advancement over previous models by using a…
Quantitative bounds on Lorentz symmetry violation in the neutrino sector have been obtained by analyzing existing laboratory data on neutron $\beta$ decay and pion leptonic decays. In particular some parameters appearing in the…
The violation of Lorentz symmetry can arise in a variety of approaches to fundamental physics. For the description of the associated low-energy effects, a dynamical framework known as the Standard-Model Extension has been developed. This…
Precision measurements of low-energy observables provide stringent tests of the Standard Model structure and accurate determinations of its parameters. An overview of the present experimental status is presented. The main topics discussed…
A sketch of our results on CPT and strings is given. A mechanism for spontaneous CPT violation in string theory is briefly reviewed, and recent theoretical progress is summarized. Possible CPT-violating contributions to a four-dimensional…
An experimental test of the Newtonian inverse square law at short range has been used to set limits on Lorentz violation in the pure gravity sector of the Standard-Model Extension. On account of the planar test mass geometry, nominally null…
We compare the Lorentz violation terms of the pure photon sector between two field theory models, namely the minimal standard model extension (SME) and the standard model supplement (SMS). From the requirement of the identity of the…
This presentation discusses some of the signals for Lorentz violation potentially observable in atomic spectroscopy and clock-comparison experiments. The emphasis of the discussion is on how the angular-momentum quantum numbers of the…
A brief introduction to the Standard-Model Extension (SME) approach to testing CPT and Lorentz symmetry is provided. Recent proposals for tests with antimatter are summarized, including gravitational and spectroscopic tests.
We investigate the compatibility of Lorentz-violating quantum field theories with the requirements of causality and stability. A general renormalizable model for free massive fermions indicates that these requirements are satisfied at low…