Threshold Corrections in the Exceptional Supersymmetric Standard Model

TL;DR

This paper calculates threshold corrections in the E6SSM, improving the precision of mass spectrum predictions and analyzing their impact on gauge coupling unification and collider phenomenology.

Contribution

It provides full expressions for threshold corrections in the E6SSM and implements them into a spectrum generator, reducing scale dependence and refining mass predictions.

Findings

Reduced matching scale dependence of mass spectra

Compatibility of the lightest Higgs mass with LHC discovery

Implications for gauge coupling unification with survival Higgs fields

Abstract

We calculate threshold corrections to the running gauge and Yukawa couplings in the Exceptional Supersymmetric Standard Model (E6SSM) and analyse the more precise and reliable mass spectra in a constrained model (CE6SSM). Full expressions for the corrections are provided and the implementation into a spectrum generator is described. We find a dramatic reduction in the matching scale dependency of the masses of many states and observe a significant adjustment of the correlation of low-scale physical masses and high-scale parameters. Still, in substantial regions of parameter space the mass of the lightest Higgs is compatible with the new boson discovered at the LHC and the model satisfies limits from collider searches for squark, gluinos and Z' bosons. We study the implications for gauge coupling unification from a new dependency of the spectrum on so-called survival Higgs fields which cannot be addressed without the inclusion of the threshold corrections.