Is the Standard Model in the Swampland? Consistency Requirements from Gravitational Scattering

Area of Science:

• Theoretical Physics
• Particle Physics
• Cosmology

Background:

• The Standard Model (SM) and General Relativity (GR) are highly successful but lack a unified description.
• Understanding the ultraviolet (UV) completion of gravity is crucial for a complete theory.

Purpose of the Study:

• To investigate the compatibility of the Standard Model with gravity using gravitational positivity bounds.
• To determine the cutoff scale of the Standard Model coupled to gravity.

Main Methods:

• Application of gravitational positivity bounds, a necessary condition for UV completable gravitational theories.
• Analysis of light-by-light scattering consistency within the Standard Model coupled to gravity.
• Consideration of Quantum Chromodynamics (QCD) and electroweak theory sectors separately.

Main Results:

• The cutoff scale for the Standard Model coupled to gravity is determined to be approximately 10^16 GeV, assuming the single-Pomeron exchange model in QCD is valid.
• If the QCD sector is excluded, the electroweak theory coupled to gravity yields a lower cutoff scale of approximately 10^13 GeV.

Conclusions:

• Gravitational positivity bounds provide a framework to probe the UV completion of quantum gravity theories coupled to matter.
• The study establishes a significant energy scale (cutoff scale) relevant for physics beyond the Standard Model and its interaction with gravity.