Quantum gravity and Lorentz invariance violation in the standard model

Area of Science:

• Fundamental Physics
• Quantum Gravity
• Cosmic Ray Physics

Background:

• Quantizing the gravitational field is a major challenge in fundamental physics.
• Experimental tests to distinguish quantum gravity theories are scarce.
• Lorentz invariance violation from quantum gravity is of recent interest but lacks concrete predictions.

Purpose of the Study:

• To demonstrate that the Standard Model inherently contains Lorentz invariance violation terms originating from quantum gravity.
• To establish a framework where these violations depend on a single, estimable parameter.
• To constrain this parameter using experimental data.

Main Methods:

• Theoretical analysis of quantum gravity effects within the Standard Model.
• Identification of Lorentz invariance violation terms.
• Estimation of the parameter controlling these effects using ultrahigh energy cosmic ray spectrum data.

Main Results:

• The Standard Model naturally incorporates tiny Lorentz invariance violation terms due to quantum gravity.
• All identified terms are governed by a single parameter, alpha, which scales the quantum gravity effects.
• Data from the ultrahigh energy cosmic ray spectrum constrain this parameter to |alpha|< approximately 10(-22)-10(-23).

Conclusions:

• The Standard Model provides a testable prediction for Lorentz invariance violation.
• Ultrahigh energy cosmic rays offer a viable experimental window to probe quantum gravity effects.
• The derived constraint on alpha offers a significant step towards experimentally validating quantum gravity theories.