Constraints on Natural Supersymmetry from Electroweak Precision Tests

TL;DR

This paper evaluates how electroweak precision tests constrain natural supersymmetry models, finding that the minimal supersymmetric standard model is marginally consistent while the NMSSM faces tighter constraints.

Contribution

It provides a detailed analysis of electroweak precision constraints on natural supersymmetry, including both MSSM and NMSSM, considering various sector bounds and Higgs mass effects.

Findings

MSSM is excluded at 68% CL but allowed at 95% CL.

NMSSM with certain parameters is excluded at 68% CL but allowed at 99% CL.

Electroweak precision tests significantly restrict natural supersymmetry parameter space.

Abstract

The observed Higgs boson mass and the naturalness argument leave us a narrow window for the soft mass spectrum in natural supersymmetry that can be studied through the electroweak precision tests (EWPTs). We divide the analysis into the Higgs sector constrained by the charged Higgs mass bound, the neutralino-chargino sector constrained by the chargino mass bound, and the third-generation squark sector tightly constrained by the observed Higgs mass. Total contributions to EWPTs in the MSSM and NMSSM are both presented. It turns out that natural MSSM is excluded at 68\% CL but consistent at 95\% CL, whereas natural NMSSM with nearly degenerate conditions is excluded at 68\% CL but consistent at 99\% CL for $\lambda\leq 0.6$.