scholarly journals Lorentz Violation, Möller Scattering, and Finite Temperature

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Alesandro F. Santos ◽  
Faqir C. Khanna

Lorentz and CPT symmetries may be violated in new physics that emerges at very high energy scale, that is, at the Planck scale. The differential cross section of the Möller scattering due to Lorentz violation at finite temperature is calculated. Lorentz-violating effects emerge from an interaction vertex due to a CPT-odd nonminimal coupling in the covariant derivative. The finite temperature effects are determined using the Thermo Field Dynamics (TFD) formalism.

2018 ◽  
Vol 33 (10n11) ◽  
pp. 1850061 ◽  
Author(s):  
A. F. Santos ◽  
Faqir C. Khanna

Gravitoelectromagnetism (GEM) is an approach for the gravitation field that is described using the formulation and terminology similar to that of electromagnetism. The Lorentz violation is considered in the formulation of GEM that is covariant in its form. In practice, such a small violation of the Lorentz symmetry may be expected in a unified theory at very high energy. In this paper, a non-minimal coupling term, which exhibits Lorentz violation, is added as a new term in the covariant form. The differential cross-section for Bhabha scattering in the GEM framework at finite temperature is calculated that includes Lorentz violation. The Thermo Field Dynamics (TFD) formalism is used to calculate the total differential cross-section at finite temperature. The contribution due to Lorentz violation is isolated from the total cross-section. It is found to be small in magnitude.


2020 ◽  
Vol 35 (26) ◽  
pp. 2050213
Author(s):  
A. F. Santos ◽  
Faqir C. Khanna

A formal analogy between the gravitational and the electromagnetic fields leads to the notion of Gravitoelectromagnetism (GEM) to describe gravitation. A Lagrangian formulation for GEM is developed for scattering processes with gravitons as an intermediate state, in addition to photons for electromagnetic scattering. The differential cross section is calculated for gravitational Möller scattering based on GEM theory. This gravitational cross section is obtained for cases where the Lorentz symmetry is maintained or violated. The Lorentz violation is introduced with the non-minimal coupling term. In addition, using the Thermo Field Dynamics formalism, thermal corrections to the differential cross section are investigated. By comparing the electromagnetic and GEM versions, of Möller scattering, it is shown that the gravitational effect may be measured at an appropriate energy scale.


Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1298
Author(s):  
José Manuel Carmona ◽  
José Luis Cortés ◽  
Lucía Pereira ◽  
José Javier Relancio

We analyze the kinematics of electron-positron production in a photon-photon interaction when one has a modification of the special relativistic kinematics as a power expansion in the inverse of a new high-energy scale. We derive the equation for the threshold energy of this reaction to first order in this expansion, including the effects due to a modification of the energy-momentum conservation equation. In contrast with the Lorentz invariance violation case, a scale of the order of a few TeV is found to be compatible with the observations of very high-energy cosmic gamma rays in the case of a modification compatible with the relativity principle.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
M. Köksal ◽  
V. Arı ◽  
A. Senol

The self-couplings of the electroweak gauge bosons are completely specified by the non-Abelian gauge nature of the Standard Model (SM). The direct study of these couplings provides a significant opportunity to test the validity of the SM and the existence of new physics beyond the SM up to the high energy scale. For this reason, we investigate the potential of the processes γγ→ZZ, e-γ→e-γ⁎γ→e-ZZ,  and e+e-→e+γ⁎γ⁎e-→e+ZZe- to examine the anomalous quartic couplings of ZZγγ vertex at the Compact Linear Collider (CLIC) with center-of-mass energy 3 TeV. We calculate 95% confidence level sensitivities on the dimension-8 parameters with various values of the integrated luminosity. We show that the best bounds on the anomalous fM2/Λ4, fM3/Λ4, fT0/Λ4, and fT9/Λ4 couplings arising from γγ→ZZ process among those three processes at center-of-mass energy of 3 TeV and integrated luminosity of Lint=2000 fb−1 are found to be [-3.30;3.30]×10-3 TeV−4, [-1.20;1.20]×10-2 TeV−4, [-3.40;3.40]×10-3 TeV−4, and [-1.80;1.80]×10-3 TeV−4, respectively.


2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Suro Kim ◽  
Toshifumi Noumi ◽  
Keito Takeuchi ◽  
Siyi Zhou

Abstract We study implications of perturbative unitarity for quasi-single field inflation with the inflaton and one massive scalar. Analyzing high energy scattering, we show that non-Gaussianities with |fNL| ≳ 1 cannot be realized without turning on interactions which violate unitarity at a high energy scale. Then, we provide a relation between fNL and the scale of new physics that is required for UV completion. In particular we find that for the Hubble scale H ≳ × 109 GeV, Planck suppressed operators can easily generate too large non-Gaussanities and so it is hard to realize successful quasi-single field inflation without introducing a mechanism to suppress quantum gravity corrections. Also we generalize the analysis to the regime where the isocurvature mode is heavy and the inflationary dynamics is captured by the inflaton effective theory. Requiring perturbative unitarity of the two-scalar UV models with the inflaton and one heavy scalar, we clarify the parameter space of the P(X, ϕ) model which is UV completable by a single heavy scalar.


2015 ◽  
Vol 30 (21) ◽  
pp. 1550106 ◽  
Author(s):  
Tatsuo Kobayashi ◽  
Osamu Seto

Recent detection of B-mode polarization induced from tensor perturbations by the BICEP2 experiment implies the so-called large field inflation, where an inflaton field takes super-Planckian expectation value during inflation, at a high energy scale. We show however, if another inflation follows hybrid inflation, the hybrid inflation can generate a large tensor perturbation with not super-Planckian but Planckian field value. This scenario would relax the tension between BICEP2 and Planck concerning the tensor-to-scalar ratio, because a negative large running can also be obtained for a certain number of e-fold of the hybrid inflation. A natural interpretation of a large gravitational wave mode with or without the scalar spectral running might be multiple inflation in the early Universe.


1975 ◽  
Vol 56 (5) ◽  
pp. 465-469 ◽  
Author(s):  
D. Amati ◽  
R. Jengo

Physics ◽  
2019 ◽  
Vol 1 (1) ◽  
pp. 92-102 ◽  
Author(s):  
Andrea Addazi ◽  
Antonino Marcianò ◽  
Roman Pasechnik

We propose direct tests of very high energy first-order phase transitions, which are elusive to collider physics, deploying the gravitational waves’ measurements. We show that first-order phase transitions lying in a large window of critical temperatures, which is considerably larger than the electroweak energy scale, can be tested from advanced LIGO (aLIGO) and the Einstein Telescope. This provides the possibility to probe several inflationary mechanisms ending with the inflaton in a false minimum and high-energy first order phase transitions that are due to new scalar bosons, beyond the Standard Model of particle physics. As an important example, we consider the axion monodromy inflationary scenario and analyze the potential for its experimental verification, deploying the gravitational wave interferometers.


2008 ◽  
Vol 77 (1) ◽  
Author(s):  
Ting-Pong Choy ◽  
Robert G. Leigh ◽  
Philip Phillips ◽  
Philip D. Powell

Symmetry ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1419 ◽  
Author(s):  
José Manuel Carmona ◽  
José Luis Cortés ◽  
José Javier Relancio ◽  
Maykoll Anthonny Reyes

The observation of cosmic neutrinos up to 2 PeV is used to put bounds on the energy scale of Lorentz invariance violation through the loss of energy due to the production of e + e - pairs in the propagation of superluminal neutrinos. A model to study this effect, which allows us to understand qualitatively the results of numerical simulations, is presented.


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