Higgs bosons near 125 GeV in the NMSSM with constraints at the GUT scale

TL;DR

This paper explores the NMSSM with GUT-scale constraints, demonstrating the possibility of a 125 GeV Higgs with enhanced diphoton decay, a lighter observable Higgs, and a viable dark matter candidate, all with modest fine-tuning.

Contribution

It presents a constrained NMSSM scenario at the GUT scale that naturally accommodates a 125 GeV Higgs and predicts additional observable Higgs states and dark matter properties.

Findings

A 125 GeV Higgs with enhanced diphoton decay is achievable.

A lighter Higgs below 123 GeV could be detected at the LHC.

Dark matter candidates with 60-90 GeV mass are consistent with WMAP and detectable by XENON100.

Abstract

We study the NMSSM with universal Susy breaking terms (besides the Higgs sector) at the GUT scale. Within this constrained parameter space, it is not difficult to find a Higgs boson with a mass of about 125 GeV and an enhanced cross section in the diphoton channel. An additional lighter Higgs boson with reduced couplings and a mass <123 GeV is potentially observable at the LHC. The NMSSM-specific Yukawa couplings lambda and kappa are relatively large and tan(beta) is small, such that lambda, kappa and the top Yukawa coupling are of order 1 at the GUT scale. The lightest stop can be as light as 105 GeV, and the fine-tuning is modest. WMAP constraints can be satisfied by a dominantly higgsino-like LSP with substantial bino, wino and singlino admixtures and a mass of ~60-90 GeV, which would potentially be detectable by XENON100.