Upperbound on Squark Masses in Gauge-Mediation Model with Light Gravitino

TL;DR

This paper derives upper bounds on squark and gluino masses in a gauge-mediated supersymmetry breaking model with a very light gravitino, based on vacuum stability considerations in the early universe.

Contribution

It provides new upper limits on superpartner masses in gauge mediation models with light gravitinos, considering thermal stability constraints.

Findings

Squark and gluino masses are constrained to be less than about 1 TeV.

The light gravitino mass is constrained to be less than 16 eV.

Vacuum stability in the early universe imposes these upper bounds.

Abstract

We examine stabilities of our supersymmetry-breaking false vacuum in a low-energy direct gauge mediation model of SUSY breaking. The stability required in the high-temperature early universe leads to upperbounds on masses of squarks and gluino as m_\tilde{q} \lesssim 1 TeV and m_\tilde{g} \lesssim 1 TeV for the light gravitino of mass m_{3/2} \lesssim 16 eV.