Clockwork inflation with non-minimal coupling

Abstract

We suggest a clockwork mechanism for a Higgs-like inflation with the non-minimal coupling term $\xi {\varphi }^{2}R$. The seemingly unnatural ratio of parameters, $\lambda /{\xi }^2\sim 10^{-10}$ of the self quartic coupling of the inflaton, $\lambda$, and the non-minimal coupling, $\xi$, is understood by exponential suppression of $\lambda$ by the clockwork mechanism, instead of a large non-minimal coupling. The portal interaction between the inflaton and the Standard Model (SM) Higgs doublet is introduced as a source of reheating and the inflaton mass. Successful realization of inflation requires that the inflaton gets a mass around (sub) GeV scale, which would lead to observable consequences depending on reheating process and its lifetime.

Comments: 6 pages, 1 figure, Minor modification in text, Refs added, Accepted for publication in European Physical Journal C