Determine the grand-unification symmetry-breaking scale

Determine the energy scale of spontaneous symmetry breaking of the grand unified gauge group in Grand Unified Theories, and quantify its relation to the scale at which the Standard Model gauge couplings unify, in order to enable precise predictions such as proton decay rates.

Background

Within Grand Unified Theories (GUTs) the Standard Model gauge groups emerge from the spontaneous breaking of a higher gauge symmetry. The precise symmetry-breaking scale sets the masses of heavy GUT states (e.g., X and Y gauge bosons) and controls predictions such as proton decay lifetimes, which scale strongly with this energy.

The paper notes that while the unification scale can be estimated (around 10^16 GeV in supersymmetric contexts), the exact symmetry-breaking scale itself is not known. Pinning down this scale would improve the interpretability of precision unification and proton decay constraints.