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Some aspects of the nonbirefringent CPT-even gauge sector of the Standard Model Extension (SME), in the vicinity of a semi-transparent mirror, are investigated in this paper. We first consider a model where the Lorentz symmetry breaking is…

High Energy Physics - Theory · Physics 2022-05-12 L. H. C. Borges , A. F. Ferrari

Spontaneous Lorentz violation realized through a nonlinear vector field constraint of the type $A_{\mu}A^{\mu}=M^{2}$ ($M$ is the proposed scale for Lorentz violation) is shown to generate massless vector Goldstone bosons, gauging the…

High Energy Physics - Theory · Physics 2008-11-26 J. L. Chkareuli , C. D. Froggatt , J. G. Jejelava , H. B. Nielsen

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…

High Energy Physics - Phenomenology · Physics 2019-11-20 Alexander Michel , Marc Sher

Light pseudoscalars, or axion like particles (ALPs), are much studied due to their potential relevance to the fields of particle physics, astrophysics and cosmology. The most relevant coupling of ALPs from the viewpoint of current…

High Energy Physics - Theory · Physics 2014-02-19 L. H. C. Borges , A. G. Dias , A. F. Ferrari , J. R. Nascimento , A. Yu. Petrov

In this proceedings, I summarize two recently discovered theoretical implications that Lorentz violation has on physical systems. First, I discuss new models for neutrino oscillations in which relatively simple combinations of…

High Energy Physics - Phenomenology · Physics 2009-11-10 Don Colladay

We show that estimates of the Lorentz symmetry violation extracted from ultra-high energy cosmic rays beyond the GZK cut-off set bounds on the parameters of a Lorentz-violating extension of the Standard Model. Moreover, we argue that…

General Relativity and Quantum Cosmology · Physics 2009-10-31 O. Bertolami

The propagation of electromagnetic waves in a Lorentz-symmetry violating scenario where there is a region of polarized vacuum is studied. It turns out that the photon field acquires an interesting polarization state, possibly useful to set…

High Energy Physics - Theory · Physics 2015-05-28 B. Agostini , F. A. Barone , F. E. Barone , Patricio Gaete , J. A. Helayël-Neto

Conceivable Lorentz-violating effects in the neutrino sector remain a research area of great general interest, as they touch upon the very foundations on which the Standard Model and our general understanding of fundamental interactions is…

High Energy Physics - Phenomenology · Physics 2020-01-16 U. D. Jentschura , I. Nandori , G. Somogyi

We examine the consequences of Lorentz violation during slow-roll inflation. We consider a canonical scalar inflaton coupled, through its potential, to the divergence of a fixed-norm timelike vector field, or "aether." The vector is…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-13 Adam R. Solomon , John D. Barrow

Spacetime-varying coupling constants can be associated with violations of local Lorentz invariance and CPT symmetry. An analytical supergravity cosmology with time-varying fine-structure constant provides an explicit example. Estimates are…

Astrophysics · Physics 2009-09-25 Alan Kostelecky , Ralf Lehnert , Malcolm Perry

The use of the vacuum lepton pair production process ($\nu \to \nu e^- e^+ $), a viable reaction for superluminal neutrinos, to put constraints on Lorentz violations requires a dynamical framework. Different choices of dynamical matrix…

High Energy Physics - Phenomenology · Physics 2012-10-01 J. M. Carmona , J. L. Cortes , D. Mazon

This article presents prospects for Lorentz-violation searches with $t\bar{t}$ at the LHC and future colliders. After a short presentation of the Standard-Model Extension as a Lorentz-symmetry-breaking effective field theory, we will focus…

High Energy Physics - Phenomenology · Physics 2019-09-06 A. Carle , N. Chanon , S. Perries

In this paper, the differential cross section for the Compton scattering process is calculated. Two types of corrections are investigated: corrections due to violation of Lorentz symmetry and thermal effects. An extended QED is considered…

High Energy Physics - Theory · Physics 2023-01-19 D. S. Cabral , A. F. Santos , Faqir C. Khanna

We investigate in detail the effects of the R-parity lepton number violation in the minimal supersymmetric standard model (MSSM) on the top-quark pair production via both $e^--e^+$ and $\gamma-\gamma$ collision modes at the linear…

High Energy Physics - Phenomenology · Physics 2009-11-10 Wang Lei , Ma Wen-Gan , Hou Hong-Sheng , Zhang Ren-You , Sun Yan-Bin

We reconsider an alternative theory of the QED with the photon as a massless vector Nambu-Goldstone boson and show that the underlying spontaneous Lorentz violation caused by the vector field vacuum expectation value, while being…

High Energy Physics - Theory · Physics 2008-11-26 J. L. Chkareuli , Z. Kepuladze , G. Tatishvili

We address the question whether a violation of Lorentz symmetry can explain the tension between the measurement and the Standard-Model prediction of the anomalous magnetic moment of the muon ($(g-2)_{\mu}$) and whether it can significantly…

High Energy Physics - Phenomenology · Physics 2022-11-30 Andreas Crivellin , Fiona Kirk , Marco Schreck

We consider the lightlike spontaneous Lorentz invariance violation (SLIV) appearing through the zero "length-fixing" constraint put on a gauge vector field, $A_{\mu }A^{\mu }=0$, and discuss its physical consequences in the framework of a…

High Energy Physics - Phenomenology · Physics 2020-07-22 J. L. Chkareuli , Z. Kepuladze

In the context of the noncommutative QED we consider few phenomena which reflect the noncommutativity. In all of them the new interactions in the Feynmann diagrams that are responsible for the deviation from the standard QED results. These…

High Energy Physics - Theory · Physics 2007-05-23 H. Arfaei , M. H. Yavartanoo

In the framework of model with Lorentz violation (LV) we discuss a physical observables for $q\bar{q}$ pair production at lepton-lepton colliders and describe the experimental signal to be detected. We obtain a conservative limits on…

High Energy Physics - Phenomenology · Physics 2017-12-18 I. S. Karpikov , D. V. Kirpichnikov , D. A. Tlisov

The classification of Lorentz- and CPT-violating operators in nonabelian gauge field theories is performed. We construct all gauge-invariant terms describing propagation and interaction in the action for fermions and gauge fields.…

High Energy Physics - Phenomenology · Physics 2019-04-03 Alan Kostelecky , Zonghao Li