Effects of Lorentz violation through the $\gamma e\to W{\nu }_e$ process in the Standard Model Extension

Abstract

Physics beyond the Fermi scale could show up through deviations of the gauge couplings predicted by the electroweak Yang-Mills sector. This possibility is explored in the context of the International Linear Collider (ILC) through the helicity amplitudes for the gamma e -> W nu_e reaction to which contributes the trilinear WWgamma coupling. The new physics effects on this vertex are parametrized in a model-independent fashion through an effective electroweak Yang-Mills sector, which is constructed by considering two essentially different sources of new physics. In one scenario, Lorentz violation will be considered exclusively as the source of new physics effects. This type of new physics is considered in an extension of the Standard Model that is known as the Standard Model Extension (SME), which is an effective field theory that contemplates CPT and Lorentz violation in a model-independent fashion. Any source of new physics that respects the Lorentz symmetry, will be considered within the general context of the well known Conventional Effective Standard Model (CESM) extension. Both the SME and the CESM descriptions include gauge invariant operators of dimension higher than four, which, in general, transform as Lorentz tensors of rank higher than zero. Whereas in the former theory observer Lorentz invariants are constructed by contracting these operators with constant Lorentz tensors, in the latter the corresponding Lorentz invariant interactions are obtained contracting such operators with products of the metric tensor. We focus our study on the possibility of experimentally distinguish both types of new physics effects on the WWgamma vertex. It is found that for a new physics scale of the same order of magnitude and under determined circumstances, both types of new physics effects will be clearly distinguished.

18 pages and 25 figures

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Cited by in corpus (11)

• Gauge field theories with Lorentz-violating operators of arbitrary dimension
• One-loop nonbirefringent effects on the electromagnetic vertex in the Standard Model Extension
• Constraining CPT-odd nonminimal interactions in the Electroweak sector
• Lorentz-violating effects on pair production of W bosons in photon collisions
• Implications of Lorentz violation on Higgs-mediated lepton flavor violation
• One-loop structure of the photon propagator in the Standard Model Extension
• Decays $Z\to \gamma \gamma$ and $Z\to gg$ in the Standard Model Extension
• Breaking of Lorentz Invariance in Electron-Proton Parity Violation
• Effects of Lorentz violation in the Higgs sector of the Minimal Standard Model Extension
• CPT-Odd effects on the electromagnetic properties of charged leptons in the Standard Model Extension
• Vacuum polarization in Yang-Mills theories with Lorentz violation