SUSY Multi-Step Unification without Doublet-Triplet Splitting

TL;DR

This paper explores a string-inspired supersymmetric GUT model predicting additional Higgs-like states, multiple unification scales, and potential collider and dark matter signatures, offering a novel approach to unification without doublet-triplet splitting.

Contribution

It proposes a new multi-step unification framework in SUSY GUTs with matter-Higgs unification, predicting extra Higgs states and multiple unification scales.

Findings

Two unification scales at 10^15 GeV and 10^18 GeV.

Presence of colored Higgs states and extra Higgs-like fields near TeV scale.

Distinct collider and dark matter phenomenology from MSSM.

Abstract

Matter-Higgs unification in string-inspired supersymmetric Grand Unified Theories predicts the existence of colored states in the Higgs multiplets and calls for two extra generations of Higgs-like fields ('unhiggses'). If these states are present near the TeV scale, gauge-coupling unification points to the existence of two distinct scales, 10^15 GeV where right-handed neutrinos and a Pati-Salam symmetry appear, and 10^18 GeV where complete unification is achieved. Baryon-number conservation, while not guaranteed, can naturally emerge from an underlying flavor symmetry. Collider signatures and dark-matter physics may be drastically different from the conventional MSSM.