Supersymmetry Breaking Scheme and The Derivation of $M_{GUT}=10^{16}GeV$ from A String Model

TL;DR

This paper proposes a modified string-inspired supersymmetry breaking scheme that naturally yields a GUT scale of 10^{16} GeV, addressing gauge symmetry breaking, the doublet-triplet problem, and mass hierarchy within string models.

Contribution

It introduces a novel mechanism involving gauge background VEVs and gaugino condensation to determine the GUT scale and solve key issues in string-inspired models.

Findings

Achieves GUT scale of 10^{16} GeV from string models.

Provides a method to generate mass hierarchies consistent with no-scale structure.

Identifies conditions on string models for large mass hierarchies.

Abstract

We propose that a modified version of string-inspired supersymmetry breaking schemes in \cite{wit2} and \cite{ross} may make affine level one SU(5) and SO(10) string models with intermediate gauge symmetry breaking scale $M_{GUT}=10^{16}GeV$ possible; doublet-triplet problem can also be solved. In particular, we propose that some charged gauge background VEVs might be turned on when gaugino condensation happens in the hidden sector and would break gauge symmetry. One can dynamically determine gaugino condensation scale, local supersymmetry breaking scale and intermediate gauge symmetry breaking scale $M_{GUT}$ in terms of dilaton VEV. With dilaton VEV, $\langle S \rangle \sim 2$, and $E_6$ hidden sector gaugino condensation, we can obtain $M_{GUT}=10^{16}GeV$. We also discuss how to generate the mass hierarchy within the framework of this supersymmetry breaking scheme. We show that the large mass hierarchy restricts string models to those that have a no-scale structure and in which the gauge coupling function does not receive string threshold corrections.