Higgs mass and unified gauge coupling in the NMSSM with Vector Matter

TL;DR

This paper explores an extended NMSSM model with vector-like matter, showing it can naturally enhance the Higgs mass to 125 GeV and possibly explain the 750 GeV diphoton resonance observed at the LHC.

Contribution

It introduces a vector-like family extension to the NMSSM that achieves a significant Higgs mass increase and maintains gauge coupling unification, offering insights into the number of generations.

Findings

40% enhancement of the Higgs mass at tree level

Potential explanation for the 750 GeV diphoton resonance

Unified gauge coupling close to unity

Abstract

We consider the NMSSM extended to include one vector-like family of quarks and leptons. If (some of) these vector-like matter particles, as the Higgs doublets, have Yukawa couplings to the singlet S that exceed unity at about the same scale $\Lambda \lesssim 10^3$ TeV, this gives the order 40 % enhancement of the tree level Higgs boson mass required in the MSSM to reach 125 GeV. It is conceivable that the Yukawa couplings to the singlet S, although naively blowing up close to $\Lambda$, will not spoil gauge coupling unification. In such a case the unified coupling $\alpha_X$ could be interestingly led to a value not far from unity, thus providing a possible explanation for the number of generations. The characteristic signal is an enhanced resonant production of neutral spin zero particles at LHC, that could even explain the putative diphoton resonance hinted by the recent LHC data at 750 GeV.