scholarly journals Lorentz violation, gravitoelectromagnetic field and Bhabha scattering

2018 ◽  
Vol 33 (02) ◽  
pp. 1850015 ◽  
Author(s):  
A. F. Santos ◽  
Faqir C. Khanna
Keyword(s):  
General Relativity ◽  
Standard Model ◽  
Cross Section ◽  
Particle Physics ◽  
Planck Scale ◽  
Lorentz Violation ◽  
Lorentz Symmetry ◽  
Standard Model Extension ◽  
Bhabha Scattering ◽  
The Standard Model

Lorentz symmetry is a fundamental symmetry in the Standard Model (SM) and in General Relativity (GR). This symmetry holds true for all models at low energies. However, at energies near the Planck scale, it is conjectured that there may be a very small violation of Lorentz symmetry. The Standard Model Extension (SME) is a quantum field theory that includes a systematic description of Lorentz symmetry violations in all sectors of particle physics and gravity. In this paper, SME is considered to study the physical process of Bhabha Scattering in the Gravitoelectromagnetism (GEM) theory. GEM is an important formalism that is valid in a suitable approximation of general relativity. A new nonminimal coupling term that violates Lorentz symmetry is used in this paper. Differential cross-section for gravitational Bhabha scattering is calculated. The Lorentz violation contributions to this GEM scattering cross-section are small and are similar in magnitude to the case of the electromagnetic field.

scholarly journals PROBING RELATIVITY USING SPACE-BASED EXPERIMENTS

2007 ◽  
Vol 16 (12b) ◽  
pp. 2469-2480 ◽  
Author(s):  
NEIL RUSSELL
Keyword(s):  
Standard Model ◽  
Special Relativity ◽  
Planck Scale ◽  
Lorentz Violation ◽  
High Sensitivity ◽  
Standard Model Extension ◽  
Full Spectrum ◽  
Small Deviations ◽  
Model Extension ◽  
The Standard Model

An overview of space tests searching for small deviations from special relativity arising at the Planck scale is given. Potential high-sensitivity space-based experiments include ones with atomic clocks, masers, and electromagnetic cavities. We show that a significant portion of the coefficient space in the Standard Model extension, a framework that covers the full spectrum of possible effects, can be accessed using space tests. Some remarks on Lorentz violation in the gravitational sector are also given.

scholarly journals Lorentz Violation of the Photon Sector in Field Theory Models

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Lingli Zhou ◽  
Bo-Qiang Ma
Keyword(s):  
Field Theory ◽  
Standard Model ◽  
Degrees Of Freedom ◽  
Lorentz Violation ◽  
Detailed Structure ◽  
Standard Model Extension ◽  
Model Extension ◽  
The Standard Model ◽  
Minimal Standard

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 intersection for the two models, we find that the free photon sector of the SMS can be a subset of the photon sector of the minimal SME. We not only obtain some relations between the SME parameters but also get some constraints on the SMS parameters from the SME parameters. The CPT-odd coefficients(kAF)αof the SME are predicted to be zero. There are 15 degrees of freedom in the Lorentz violation matrixΔαβof free photons of the SMS related with the same number of degrees of freedom in the tensor coefficients(kF)αβμν, which are independent from each other in the minimal SME but are interrelated in the intersection of the SMS and the minimal SME. With the related degrees of freedom, we obtain the conservative constraints(2σ)on the elements of the photon Lorentz violation matrix. The detailed structure of the photon Lorentz violation matrix suggests some applications to the Lorentz violation experiments for photons.

Role of gravity in particle physics: A unified approach

2020 ◽  
Vol 29 (11) ◽  
pp. 2041012
Author(s):  
Pedro D. Alvarez ◽  
Mauricio Valenzuela ◽  
Jorge Zanelli
Keyword(s):  
General Relativity ◽  
Standard Model ◽  
Particle Physics ◽  
Laws Of Nature ◽  
Lorentz Transformations ◽  
Unified Approach ◽  
The Standard Model ◽  
Matter Fields

General Relativity (GR) and the Standard Model (SM) of particle physics are two enormously successful frameworks for our understanding the fundamental laws of nature. However, these theoretical schemes are widely disconnected, logically independent and unrelated in scope. Yet, GR and SM at some point must intersect, producing claims about phenomena that should be reconciled. Be it as it may, both schemes share a common basic ground: symmetry under local Lorentz transformations. Here, we will focus on the consequences of assuming this feature from the beginning to combine geometry, matter fields and gauge interactions. We give a rough description of how this could be instrumental for the construction of a unified scheme of gravitation and particle physics.

scholarly journals Effects of Lorentz violation through the γe → Wνe process in the Standard Model extension

2014 ◽  
Vol 41 (5) ◽  
pp. 055003 ◽  
Author(s):  
J I Aranda ◽  
F Ramírez-Zavaleta ◽  
D A Rosete ◽  
F J Tlachino ◽  
J J Toscano ◽  
...  
Keyword(s):  
Standard Model ◽  
Lorentz Violation ◽  
Standard Model Extension ◽  
Model Extension ◽  
The Standard Model

scholarly journals NEW CHANCE FOR RESEARCHES ON LORENTZ VIOLATION

2012 ◽  
Vol 10 ◽  
pp. 195-206 ◽  
Author(s):  
BO-QIANG MA
Keyword(s):  
Field Theory ◽  
Standard Model ◽  
Effective Field Theory ◽  
Lorentz Violation ◽  
Phenomenological Analysis ◽  
Effective Field ◽  
Standard Model Extension ◽  
Model Extension ◽  
The Standard Model

I present a brief review on the motivation for the study on Lorentz violation and on some of our studies with phenomenological analysis of Lorentz violation effects. I also discuss three effective field theory frameworks for Lorentz violation: the Coleman-Glashow model, the standard model extension (SME), and the standard model supplement (SMS). The situation of the OPERA "anomaly" is also briefly reviewed, together with some discussion on the superluminality of neutrinos within the effective field theory frameworks.

scholarly journals TESTS OF LORENTZ AND CPT VIOLATION WITH MiniBooNE NEUTRINO OSCILLATION EXCESSES

2012 ◽  
Vol 27 (25) ◽  
pp. 1230024 ◽  
Author(s):  
TEPPEI KATORI
Keyword(s):  
Standard Model ◽  
Neutrino Oscillation ◽  
Lorentz Invariance ◽  
Planck Scale ◽  
Lorentz Violation ◽  
New Physics ◽  
Cpt Symmetry ◽  
Standard Model Extension ◽  
Sidereal Time ◽  
Short Baseline

Violation of Lorentz invariance and CPT symmetry is a predicted phenomenon of Planck-scale physics. Various types of data are analyzed to search for Lorentz violation under the Standard Model Extension (SME) framework, including neutrino oscillation data. MiniBooNE is a short-baseline neutrino oscillation experiment at Fermilab. The measured excesses from MiniBooNE cannot be reconciled within the neutrino Standard Model (νSM); thus it might be a signal of new physics, such as Lorentz violation. We have analyzed the sidereal time-dependence of MiniBooNE data for signals of the possible breakdown of Lorentz invariance in neutrinos. In this brief review, we introduce Lorentz violation, the neutrino sector of the SME and the analysis of short-baseline neutrino oscillation experiments. We then present the results of the search for Lorentz violation in MiniBooNE data. This review is based on the published result.

scholarly journals Lorentz-violating effects on pair production of W bosons in photon collisions

2014 ◽  
Vol 29 (31) ◽  
pp. 1450180 ◽  
Author(s):  
J. I. Aranda ◽  
F. Ramírez-Zavaleta ◽  
F. J. Tlachino ◽  
J. J. Toscano ◽  
E. S. Tututi
Keyword(s):  
Standard Model ◽  
Polarization State ◽  
New Physics ◽  
Lorentz Symmetry ◽  
Energy Scale ◽  
Lagrangian Model ◽  
Standard Model Extension ◽  
Symmetry Violation ◽  
Model Extension ◽  
The Standard Model

We examine Lorentz-violating effects that could appear through deviations of the Standard Model gauge couplings WWγ, WWγγ, Zγγ and γγγ. These new physics effects are explored on the γγ→WW reaction at possible future Linear Colliders. In particular, the associated helicity amplitudes are computed in the context of the Standard Model Extension (which is a model that includes Lorentz violation) and the Effective Lagrangian Model (which incorporates new physics effects that respect Lorentz symmetry). We perform an exhaustive study of the polarized differential cross-sections to stand out effects related to Lorentz symmetry violation, where it is evidenced that the effects of Lorentz symmetry violation are more sensitive to the presence of the e background field. We found that for the (±, ±, (L, T+T, L)) polarization state, only Standard Model Extension contributes at the lowest order. For this polarization state, with an integrated luminosity assumed to be 103 fb -1, we estimated up to 1 event for a Lorentz-violating energy scale of 44 TeV.

scholarly journals Constraints on Space-Time-Matter Theory in the Framework of the Standard-Model Extension

Galaxies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 26
Author(s):  
James Overduin ◽  
Hamna Ali ◽  
Francis Walz
Keyword(s):  
Standard Model ◽  
Rest Mass ◽  
Lorentz Violation ◽  
Space Time ◽  
Standard Model Extension ◽  
Matter Theory ◽  
Model Extension ◽  
The Standard Model ◽  
Klein Theory ◽  
Kaluza Klein

We use experimental limits on Lorentz violation within the framework of the Standard-Model Extension to derive quantitative constraints on Space-Time-Matter theory, a version of Kaluza–Klein theory in which the cylinder condition is relaxed so that four-dimensional physics can in principle depend on the extra coordinates. The extra dimensions are not necessarily compact or length-like. We find that the associated variation in fundamental quantities such as rest mass must occur slowly, on cosmological scales.

scholarly journals Lorentz violation and gravity

2009 ◽  
Vol 5 (S261) ◽  
pp. 409-413
Author(s):  
Quentin G. Bailey
Keyword(s):  
Standard Model ◽  
Lorentz Violation ◽  
Laser Ranging ◽  
Unified Theory ◽  
Standard Model Extension ◽  
Lunar Laser Ranging ◽  
Lunar Laser ◽  
Model Extension ◽  
The Standard Model

AbstractIn the last decade, a variety of high-precision experiments have searched for miniscule violations of Lorentz symmetry. These searches are largely motivated by the possibility of uncovering experimental signatures from a fundamental unified theory. Experimental results are reported in the framework called the Standard-Model Extension (SME), which describes general Lorentz violation for each particle species in terms of its coefficients for Lorentz violation. Recently, the role of gravitational experiments in probing the SME has been explored in the literature. In this talk, I will summarize theoretical and experimental aspects of these works. I will also discuss recent lunar laser ranging and atom interferometer experiments, which place stringent constraints on gravity coefficients for Lorentz violation.

scholarly journals Is There Any Symmetry Left in Gravity Theories with Explicit Lorentz Violation?

Symmetry ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 433 ◽  
Author(s):  
Yuri Bonder ◽  
Cristóbal Corral
Keyword(s):  
Standard Model ◽  
Lorentz Violation ◽  
The Other ◽  
Standard Model Extension ◽  
Robust Algorithm ◽  
First Order ◽  
Other Hand ◽  
Model Extension ◽  
The Standard Model ◽  
Theories Of Gravity

It is well known that a theory with explicit Lorentz violation is not invariant under diffeomorphisms. On the other hand, for geometrical theories of gravity, there are alternative transformations, which can be best defined within the first-order formalism and that can be regarded as a set of improved diffeomorphisms. These symmetries are known as local translations, and among other features, they are Lorentz covariant off shell. It is thus interesting to study if theories with explicit Lorentz violation are invariant under local translations. In this work, an example of such a theory, known as the minimal gravity sector of the Standard Model Extension, is analyzed. Using a robust algorithm, it is shown that local translations are not a symmetry of the theory. It remains to be seen if local translations are spontaneously broken under spontaneous Lorentz violation, which are regarded as a more natural alternative when spacetime is dynamic.

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