Hybrid Inflation and Baryogenesis at the TeV Scale

TL;DR

The paper explores TeV-scale inverted hybrid inflation with a inflaton-Higgs coupling as a framework for electroweak baryogenesis. Ordinary hybrid inflation is ruled out at this scale due to loop corrections, hence the inverted approach requiring extreme counterterm cancellations to maintain flatness and COBE normalization. Two baryogenesis pathways are analyzed: non-thermal EW restoration with Higgs winding produced during preheating, and zero-temperature production via the Kibble mechanism at the end of inflation; both rely on specific, finely-tuned parameter regions (notably p=5, q=6) and a reheat temperature below the EW scale to avoid sphaleron washout. The work demonstrates a self-consistent albeit finely-tuned route from TeV-scale inflation to the observed baryon asymmetry, highlighting potential collider-testable implications and the delicate balance of quantum corrections in low-scale inflation models.

Abstract

We consider the construction of inverted hybrid inflation models in which the vacuum energy during inflation is at the TeV scale, and the inflaton couples to the Higgs field. Such models are of interest in the context of some recently proposed models of electroweak baryogenesis. We demonstrate how constraints on these models arise from quantum corrections, and how self-consistent examples may be constructed, albeit at the expense of fine-tuning. We discuss two possible ways in which the baryon asymmetry of the universe may be produced in these models. One of them is based on preheating and a consequent non-thermal electroweak symmetry restoration and the other on the formation of Higgs winding configurations by the Kibble mechanism at the end of inflation.

Figures (3)

• Figure 1: The inflaton potential at $g=0.163$ and $m^2=71000$ GeV$^2$. The solid line shows the true minimum at each $\sigma$ and the dashed line shows the saddle point that corresponds to $\phi=0$. The dotted line shows the frequency of the inflaton oscillations as a function of $\sigma_a$.
• Figure 2: The plot of the allowed region of the parameter space. a) $p=5$, $q=6$, b) $p=6$, $q=8$. In this case, we haven't plotted the frequency contours, because the frequency is almost everywhere very high.
• Figure 3: a) The region of the parameter space where baryogenesis from the Kibble mechanism is possible. b) The potential at $g=0.2$, $m^2=1000$ GeV$^2$.