Constraints on Natural SUSY from Electroweak Precision Tests

Sibo Zheng, Yao Yu

Published 2014-05-26, updated 2014-09-11Version 2

The soft mass spectrum for Natural supersymmetry are lower bounded above $\sim$ a few hundred GeVs by the LHC experiments, whereas upper bounded below $\sim$ 1 TeV by {\it naturalness}. It is viable and useful to study so constrained spectrum in light of electroweak precision tests (EWPTs). We divide the analysis into three seperate sets, i.e., the Higgs sector constrained by charged Higgs mass bound, the neutralino-chargino sector constrained by chargino mass bound, and the third-generation squark sector constrained by Higgs mass. Contributions to EWPTs are analyzed in both MSSM and NMSSM. The total contribution is then combined. It turns out that Natural MSSM is excluded at 99\% CL, whereas Natural NMSSM with nearly degenerate conditions is excluded at 68\% CL but consistent at 99\% CL for either $\mu\leq 1$ TeV or $\lambda\leq 0.6$.