Natural origin of inflation within a class of supersymmetric preon models

Derivation of a desired potential for implementing the idea of new inflation from an underlying theory of particle physics has so far remained a challenging task in that it requires unusually small quartic coupling (∼${10}^{\mathrm{-}13\pm 1}$) and an even smaller mass term for the relevant field (the inflaton) in units of its true vacuum expectation value. It is shown that a class of viable locally supersymmetric preon models naturally give rise to the desired potential for a composite field ${\Delta }_R$ commonly used as a Higgs field to break left-right symmetry and B-L, so that ${\Delta }_R$ can serve as the inflaton. We show that both the quartic coupling and the mass of ${\Delta }_R$ vanish in the limit of supersymmetry, U(1${)}_{\mathrm{X}}$, U(1${)}_{\mathrm{V}}$ and gauge invariance. Radiative corrections, in the presence of soft supersymmetry-breaking mass terms, which arise dynamically in the model, give rise to a miniscule quartic coupling and a negligible mass for ${\Delta }_R$, just as desired. This turns out to be the case in spite of the fact that ${\Delta }_R$ is a gauge nonsinglet.