XENON100 Implications for Naturalness in the MSSM, NMSSM and lambda-SUSY

TL;DR

This paper examines how recent XENON100 dark matter detection limits impact the naturalness of electroweak symmetry breaking in MSSM, NMSSM, and lambda-SUSY models, highlighting that lambda-SUSY remains largely natural and testable.

Contribution

It extends previous correlation studies between dark matter detection and fine-tuning to NMSSM and lambda-SUSY, analyzing experimental constraints on naturalness in these models.

Findings

Most low fine-tuning parameter space in MSSM and NMSSM is excluded by XENON100.

lambda-SUSY allows for more natural electroweak symmetry breaking due to suppressed fine-tuning.

Upcoming XENON1T will test most of the natural parameter space in all three models.

Abstract

In a recent paper arXiv:1107.5048, we discussed the correlation between the elastic neutralino-nucleon scattering cross section, constrained by dark matter direct detection experiments, and fine-tuning at tree-level in the electroweak symmetry breaking sector of the Minimal Supersymmetric Standard Model (MSSM). Here, we show that the correlation persists in the Next-to-Minimal Supersymmetric Standard Model (NMSSM), and its variant, lambda-SUSY. Both models are strongly motivated by the recent discovery of a 125 GeV Higgs-like particle. We also discuss the implications of the recently published bound on the direct detection cross section from 225 live days of XENON100 experiment. In both the MSSM and the NMSSM, most of the parameter space with fine-tuning less than 10% is inconsistent with the XENON100 bound. In lambda-SUSY, on the other hand, large regions of completely natural electroweak symmetry breaking are still allowed, primarily due to a parametric suppression of fine-tuning with large \lambda. The upcoming XENON1T experiment will be able to probe most of the parameter space with less than 1% fine-tuning in all three models.