Gauge mediation without gravitino problem by virtue of the QCD anomaly

Nobuki Yoshimatsu

doi:10.1103/physrevd.100.096017

Abstract

We consider the possibility that the Peccei-Quinn charged dynamical supersymmetry breaking (DSB) mechanism readily accommodates gauge mediation without the gravitino problem. Given a gravitino of ${m}_{3/2}=\mathcal{O}(\mathrm{eV})$ for the Intriligator-Seiberg-Shih model, an axion, converted from a Nambu-Goldstone boson, could become a dark matter candidate, while the QCD anomaly and a sizable $\ensuremath{\mu}$ value are naturally generated. We also stress that rather minimal DSB content is sufficient to yield the observed mass of the lightest Higgs boson, other than the acceptable soft mass of sparticles in the observable sector.

Highlights

Gauge-mediated supersymmetry (SUSY) breaking [1] has been recognized as a promising mechanism that plausibly communicates with the minimal supersymmetric standard model (MSSM) sector, mainly because the gauginos and sfermions acquire the flavor universal soft mass, leading to the highly suppressed flavor changing process
The gravitino problem might be unavoidably encountered; the relic density of the stable gravitino with 1 keV < m3=2 < 1 GeV implies a low reheating temperature, i.e., TR ≲ 106 GeV, which seriously conflicts with the thermal leptogenesis [2,3,4]
A lighter gravitino (m3=2 < Oð100Þ eV) serves as warm dark matter (DM), which might be incompatible with the observed structure of the Universe that strongly suggests the bottomup type of galaxy formation

Summary

INTRODUCTION

Gauge-mediated supersymmetry (SUSY) breaking [1] has been recognized as a promising mechanism that plausibly communicates with the minimal supersymmetric standard model (MSSM) sector, mainly because the gauginos and sfermions acquire the flavor universal soft mass, leading to the highly suppressed flavor changing process. This study shows that, via suitable R charge assignment, the axion may become a good DM candidate even for TR > 109 GeV Therein, it follows that m3=2 1⁄4 O (eV) and msoft ðthe MSSM soft massÞ ≃ 1 TeV. We conclude that the axino has the mass of Oð10−6Þ eV, and should be long lived (or might be stable) At this point, notice that the thermal relics should be estimated as follows: Ωah2 ≲ 5.8 × 105 ma 1 GeV ð26Þ and the saxion and the axino could be expressed as s 1⁄4 s1p−ffiffis1 ;. Ð32Þ and ΛEW 1⁄4 Oð100Þ GeV is the electroweak symmetry breaking scale, while ms, mW denote the saxion and the weak boson mass, respectively. We deduce that the observed DM relics should predominantly comprise the axion as fa is close to 1012 GeV

THE OTHER MASS SPECTRUM

ENHANCING THE LIGHTEST HIGGS MASS

DISCUSSION

CONCLUSION