A natural Coleman-Weinberg theory explains the diphoton excess

TL;DR

This paper explores a Coleman-Weinberg based model with an extra scalar and fermions to explain the 750 GeV diphoton excess, ensuring naturalness and perturbative control within a constrained framework.

Contribution

It extends previous Coleman-Weinberg models by analyzing scalar mass differences and demonstrates their potential to account for the diphoton excess with testable LHC signatures.

Findings

Model can explain the 750 GeV diphoton excess

Perturbative control maintained up to just above heavy states

Predicts testable signatures at the LHC

Abstract

It is possible to delay the hierarchy problem, by replacing the standard Higgs-sector by the Coleman-Weinberg mechanism, and at the same time ensure perturbative naturalness through the so-called Veltman conditions. As we showed in a previous study, minimal models of this type require the introduction of an extra singlet scalar further coupled to new fermions. In this constrained setup the Higgs mass was close to the observed value and the new scalar mass was below a TeV scale. Here we first extend the previous analysis by taking into account the important difference between running mass and pole mass of the scalar states. We then investigate whether these theories can account for the 750 GeV excess in diphotons observed by the LHC collaborations. New QCD-colored fermions in the TeV mass range coupled to the new scalar state are needed to describe the excess. We further show, by explicit computation of the running of the couplings, that the model is under perturbative control till just above the masses of the heaviest states of the theory. We further suggest related testable signatures and thereby show that the LHC experiments can test these models.