Cosmological Fine Tuning, Supersymmetry, and the Gauge Heirarchy Problem

Abstract

We study the extent to which the cosmological fine-tuning problem - why the relic density of neutralino cold dark matter particles $\chi$ is similar to that of baryons - is related to the fine-tuning aspect of the gauge hierarchy problem - how one arranges that M_W << M_P without unnatural choices of MSSM parameters. Working in the minimal supergravity framework with universal soft supersymmetry-breaking parameters as inputs, we find that the hierarchical fine tuning is minimized for Ω_χ h^2 \sim 0.1. Conversely, imposing Ω_χ h^2 < 1 does not require small hierarchical fine tuning, but the exceptions to this rule are rather special, with parameters chosen such that m_χ\sim M_Z/2 or M_h/2, or else m_χ \simgt m_t. In the first two cases, neutralino annihilation receives a large contribution from a direct-channel pole, whereas in the third case it is enhanced by the large top Yukawa coupling.

9 pages, latex, 7 ps figures

References in corpus (4)

• Charginos and Neutralinos in the Light of Radiative Corrections: Sealing the Fate of Higgsino Dark Matter
• The fine-tuning price of LEP
• Constraints on Neutralino Dark Matter from LEP 2 and Cosmology
• About the fine-tuning price of LEP

Cited by in corpus (11)

• Calculations of Neutralino-Stau Coannihilation Channels and the Cosmologically Relevant Region of MSSM Parameter Space
• Supersymmetric Dark Matter in the Light of LEP and the Tevatron Collider
• How Finely Tuned is Supersymmetric Dark Matter?
• Testing SUSY at the LHC: Electroweak and Dark matter fine tuning at two-loop order
• A New Measure of Fine Tuning
• Energy nonconservation as a link between $f(R,T)$ gravity and noncommutative quantum theory
• Testing SUSY
• Supersymmetric Dark Matter and the Energy of a Linear Electron-Positron Collider
• Flavored Co-annihilations
• Physics Beyond the Multiverse - Naturalness and the Quest for a Fundamental Theory
• Naturalness of electroweak physics within minimal supergravity