Cosmological Constant in SUGRA Models with Degenerate Vacua

Colin Froggatt,Anthony Thomas,Roman Nevzorov,Holger Nielsen

doi:10.3390/universe5100214

Abstract

The extrapolation of couplings up to the Planck scale within the standard model (SM) indicates that the Higgs effective potential can have two almost degenerate vacua, which were predicted by the multiple point principle (MPP). The application of the MPP to ( N = 1 ) supergravity (SUGRA) implies that the SUGRA scalar potential of the hidden sector possesses at least two exactly degenerate minima. The first minimum is associated with the physical phase in which we live. In the second supersymmetric (SUSY) Minkowski vacuum, the local SUSY may be broken dynamically, inducing a tiny vacuum energy density. In this paper, we consider the no-scale-inspired SUGRA model in which the MPP conditions are fulfilled without any extra fine-tuning at the tree-level. Assuming that at high energies, the couplings in both phases are identical, one can estimate the dark energy density in these vacua. Using the two-loop renormalization group (RG) equations, we find that the measured value of the cosmological constant can be reproduced if the SUSY breaking scale M S in the physical phase is of the order of 100 TeV. The scenario with the Planck scale SUSY breaking is also discussed.

Highlights

The discovery of the Higgs boson with a mass M H around 125 GeV constitutes a crucial step towards our understanding of the mechanism of the electroweak (EW) symmetry breaking
The gravitino and all the scalar particles get m3/2 ξ σ. It can be identified with the physical vacuum
When local SUSY is broken near the Planck scale in the physical vacuum, the contribution induced in the visible sector to the total vacuum energy density in the second phase tends to be negligibly small

Summary

Introduction

The discovery of the Higgs boson with a mass M H around 125 GeV constitutes a crucial step towards our understanding of the mechanism of the electroweak (EW) symmetry breaking. According to the MPP, this second vacuum and the physical one must have the same energy density Such a second vacuum is realised only when the SUGRA scalar potential has a minimum where the superpotential W for the hidden sector and its derivatives vanish, i.e.,. The absolute value of the vacuum energy density at the minimum of the SUGRA scalar potential (8) tends to be of the order of m23/2 M2Pl. To demonstrate this, let us suppose that the function. The structure of the potential (16) leads to a supersymmetric particle spectrum at low energies, and the invariance of the Kähler function with respect to symmetry transformations (12) and (13) prevents the breaking of local SUSY [13]

No-Scale Inspired SUGRA Model with Degenerate Vacua

Dark Energy Density in the Models with the Low SUSY Breaking Scale

Summary and Concluding Remarks