Quantum Gravity and Lorentz invariance violation in the Standard Model

TL;DR

This paper demonstrates that the Standard Model inherently contains tiny Lorentz invariance violation terms originating from quantum gravity effects, with a single parameter estimated from cosmic ray data.

Contribution

It reveals that the Standard Model includes intrinsic LIV terms from quantum gravity, reducing reliance on arbitrary assumptions in LIV predictions.

Findings

LIV terms in the Standard Model depend on one parameter, α.

Estimated α from cosmic ray data is less than ~10^{-22} to 10^{-23}.

Provides a potential experimental probe for quantum gravity effects.

Abstract

The most important problem of fundamental Physics is the quantization of the gravitational field. A main difficulty is the lack of available experimental tests that discriminate among the theories proposed to quantize gravity. Recently, Lorentz invariance violation by Quantum Gravity(QG) have been the source of a growing interest. However, the predictions depend on ad-hoc hypothesis and too many arbitrary parameters. Here we show that the Standard Model(SM) itself contains tiny Lorentz invariance violation(LIV) terms coming from QG. All terms depend on one arbitrary parameter $\alpha$ that set the scale of QG effects. This parameter can be estimated using data from the Ultra High Energy Cosmic Rays spectrum to be $|\alpha|<\sim 10^{-22}-10^{-23}$.