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

Abstract

We revisit the viable parameter space in No-Scale 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 Bµ 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 F-SU (5) returns as a King after the spurious 750 GeV diphoton excess was gone with the wind.

Spinning no-scale $${\mathcal {F}}$$-SU(5) in the right direction

“…In these prior phenomenological works, the model complied with all BSM experiments, the one notable exception being the SUSY contribution to the anomalous magnetic moment of the muon. Neglecting the contribution of additional vector-like multiplets introduced into No-Scale F-SU (5) from its outset, the computed SUSY contribution persisted near a μ (SUSY) ∼ 1 × 10 −10 [37,41,43,44]. Whereas this was consistent with the 3σ intervals −17.1 × 10 −10 ≤ a μ ≤ 43.8 × 10 −10 obtained from the original BNL experiment [31], the tension with the BNL central value was nonetheless worrisome.…”

“…1, where only actual computed points are plot, borrowed from all the benchmark sets published in Refs. [37][38][39][41][42][43][44]. This Fig.…”

“…Only actual computed points are plot, borrowed from all the benchmark sets published in Refs. [37][38][39][41][42][43][44] violation and flavour changing neutral currents, and a twostep see-saw mechanism for neutrino masses [64,65].…”

“…1 using all the benchmark sets published in Refs. [37][38][39][41][42][43][44]. The proportional dependence of all SUSY mass parameters upon this single unified mass term M 1/2 prevents any explicit dialing up of desirable solutions right from the start.…”

“…The phenomenology of the supersymmetric grand unified theory (GUT) model No-Scale F-SU (5) has been well studied and documented (for example, see Refs. [33][34][35][36][37][38][39][40][41][42][43][44]). Tantamount to these compelling phenomenological developments, recent cosmological work demonstrated the derivation of a complete Starobinsky-like inflationary model from superstring theory within No-Scale Flipped SU (5), all while also generating right-handed neutrino masses that can alleviate the baryon asymmetry of our universe [45], described as a "λ 6 Universe" (for instance, see Refs.…”