The Return of the King: No-Scale ${\cal F}$-$SU(5)$

TL;DR

This paper analyzes the parameter space of No-Scale ${ m F}$-$SU(5)$, showing that current LHC gluino mass limits imply a lower bound around 1.9 TeV, explaining the lack of supersymmetry signals and addressing the 750 GeV resonance issue.

Contribution

It provides a detailed revisit of No-Scale ${ m F}$-$SU(5)$ parameter space in light of LHC constraints, highlighting the implications for gluino masses and the 750 GeV resonance.

Findings

Gluino mass lower limit is about 1.9 TeV.

The model explains the absence of supersymmetry signals at the LHC.

The model cannot account for the 750 GeV diphoton resonance.

Abstract

We revisit the viable parameter space in No-Scale ${\cal F}$-$SU(5)$, examining the Grand Unified Theory within the context of the prevailing gluino mass limits established by the LHC. The satisfaction of both the No-Scale boundary condition and the experimentally measured Standard Model (SM) like Higgs boson mass requires a lower limit on the gluino mass in the model space of about 1.9 TeV, which maybe not coincidentally is the current LHC supersymmetry search bound. This offers a plausible explanation as to why a supersymmetry signal has thus far not been observed at the LHC. On the contrary, since the vector-like flippon particles are relatively heavy due to the strict condition that the supersymmetry breaking soft term $B_{\mu}$ must vanish at the unification scale, we also cannot address the recently vanished 750 GeV diphoton resonance at the 13 TeV LHC. Therefore, No-Scale ${\cal F}$-$SU(5)$ returns as a King after the spurious 750 GeV diphoton excess was gone with the wind.