Coupling Unification, GUT-Scale Baryogenesis and Neutron-Antineutron Oscillation in SO(10)

TL;DR

This paper demonstrates that non-supersymmetric SO(10) models with a TeV-scale color-sextet scalar can unify gauge couplings, enable neutron-antineutron oscillations, and support low-scale baryogenesis, with testable predictions for collider and oscillation experiments.

Contribution

It introduces a class of SO(10) models with a TeV-scale scalar that unify gauge couplings and explain baryogenesis and neutron-antineutron oscillations.

Findings

Gauge coupling unification achieved in non-supersymmetric SO(10) models.

Predicted neutron-antineutron oscillation time within experimental reach.

Scalar remnants of the seesaw mechanism accessible at the LHC.

Abstract

We show that unification of the three gauge couplings can be realized consistently in a class of non-supersymmetric SO(10) models with a one-step breaking to the Standard Model if a color-sextet scalar field survives down to the TeV scale. Such scalars, which should be accessible to the LHC for direct detection, arise naturally in SO(10) as remnants of the seesaw mechanism for neutrino masses. The diquark couplings of these scalars lead to \Delta B = 2 baryon number violating processes such as neutron-antineutron oscillation. We estimate the free neutron-antineutron transition time to be \tau_{n-\bar{n}} \approx (10^9-10^{12}) sec., which is in the interesting range for next generation n-\bar{n} oscillation experiments. These models also realize naturally the recently proposed (B-L)-violating GUT scale baryogenesis which survives to low temperatures unaffected by the electroweak sphaleron interactions.