Supersymmetry and SU(2)xU(1) breaking with naturally vanishing vacuum energy

TL;DR

This paper demonstrates a model where supersymmetry and gauge symmetry break simultaneously with zero vacuum energy, with key parameters determined by quantum effects, offering a novel approach to particle physics and cosmology.

Contribution

It presents a superstring effective supergravity model with simultaneous symmetry breaking and vanishing vacuum energy, where fundamental scales are set by quantum corrections.

Findings

Supersymmetry and gauge symmetry break at the classical level with zero vacuum energy.

Key physical scales are dynamically determined by quantum effects.

The model features a goldstino component along the higgsino direction.

Abstract

We show how the spontaneous breaking of local N=1 supersymmetry and of the SU(2)xU(1) gauge symmetry can be simultaneously realized, with naturally vanishing tree-level vacuum energy, in superstring effective supergravities. Both the gravitino mass m_{3/2} and the electroweak scale m_Z are classically undetermined, and slide along moduli directions that include the Higgs flat direction |H_1^0| = |H_2^0|. There are important differences with conventional supergravity models: the goldstino has components along the higgsino direction; SU(2) x U(1) breaking occurs already at the classical level; the scales m_{3/2} and m_Z, the gauge couplings, the lightest Higgs mass and the cosmological constant are entirely determined by quantum corrections.