Lorentz-Violating Running of Coupling Constants

TL;DR

This paper investigates how Lorentz-violating effects influence the running of coupling constants in quantum electrodynamics and quantum chromodynamics, highlighting the dominance of different terms at various energy scales and potential observable consequences.

Contribution

It provides a detailed calculation of the vacuum polarization tensor in Lorentz-violating QED and explores the implications for the running of couplings and observable effects in QCD.

Findings

Low-energy limit dominated by Chern-Simons-like term

High-energy limit influenced by c-type coefficients

Potential observable effects on parton distribution functions

Abstract

We compute the full vacuum polarization tensor in the minimal QED extension. We find that its low-energy limit is dominated by the radiatively induced Chern-Simons-like term and the high-energy limit is dominated by the c-type coefficients. We investigate the implications of the high-energy limit for the QED and QCD running couplings. In particular, the QCD running offers the possibility to study Lorentz-violating effects on the parton distribution functions and observables such as the hadronic R ratio.