Grand Unification, Axion, and Inflation in Intermediate Scale Supersymmetry

Understand

A class of supersymmetric grand unified theories is introduced that has a single scale below the cutoff, that of the supersymmetry breaking masses $\tilde{m}$.

• For a wide range of the dimensionless parameters, agreement with the observed mass of the Higgs boson determines $\tilde{m} \sim 10^9-10^{13} {\rm GeV}$, yielding Intermediate Scale Supersymmetry.
• We show that within this framework it is possible for seesaw neutrino masses, axions, and inflation to be described by the scale $\tilde{m}$, offering the possibility of a unified origin of disparate phenomena.
• Neutrino masses allowing for thermal leptogenesis can be obtained, and the axion decay constant lies naturally in the range $f_a \sim 10^9-10^{11} {\rm GeV}$, consistent with a recent observational suggestion of high scale inflation.