Fun with colours: the standard model with two colour QCD has radically different long distance physics

TL;DR

This paper explores how replacing the three-colour QCD in the standard model with a two-colour version drastically alters long-distance physics, impacting nuclear, atomic, and cosmic phenomena.

Contribution

It investigates the effects of a two-colour QCD within the standard model, revealing significant long-distance and cosmological implications.

Findings

Minor changes at the hadronic scale cascade to nuclear and atomic physics

Altered QCD affects the evolution of stars and galaxies

Universe's physics is highly sensitive to quark-scale modifications

Abstract

In our world the standard model of particle physics contains within it the fairly intractable theory called QCD. A toy version with two colours is often studied as a model confining and chiral symmetry breaking field theory. Here we investigate the cascade of changes at various distance scales if we make this change within the standard model. It is possible to limit the changes at the hadronic scale. However, the minor changes that occur actually cascade down to the far infrared, into nuclear and atomic physics, and chemistry. Through this it also possibly affects the evolution of stars and galaxies. We remark on this unexpected sensitivity of the universe to physics at the scale of quarks.