Minimal Natural Supersymmetry after the LHC8

TL;DR

This paper evaluates minimal natural supersymmetry models against LHC Run 1 data, identifying allowed and excluded parameter regions based on extensive search analyses, with a focus on light higgsinos, stops, and gluinos.

Contribution

It provides a comprehensive analysis of 22,000 minimal natural SUSY scenarios using public tools, delineating the parameter space allowed by LHC data.

Findings

Scenarios with $m_{\tilde t_1} < 230$ GeV are excluded.

Scenarios with $m_{\tilde g} < 440$ GeV are excluded.

Models with $m_{\tilde t_1} > 660$ GeV and $m_{\tilde g} > 1180$ GeV remain allowed.

Abstract

In this work, we present limits on natural supersymmetry scenarios based on searches in data taken during run 1 of the LHC. We consider a set of 22000 model points in a six dimensional parameter space. These scenarios are minimal in the sense of only keeping those superparticles relatively light that are required to cancel the leading quadratically divergent quantum corrections (from the top and QCD sector) to the Higgs mass in the Standard Model. The resulting mass spectra feature higgsinos as the lightest supersymmetric particle, as well as relatively light third generation $SU(2)$ doublet squarks and $SU(2)$ singlet stops and gluinos while assuming a Standard Model like Higgs boson. All remaining supersymmetric particles and Higgs bosons are assumed to be decoupled. We check each parameter set against a large number of LHC searches as implemented in the public code {\tt CheckMATE}. These searches show a considerable degree of complementarity, i.e. in general many searches have to be considered in order to check whether a given scenario is allowed. We delineate allowed and excluded regions in parameter space. For example, we find that all scenarios where either $m_{\tilde t_1} < 230$ GeV or $m_{\tilde g} < 440$ GeV are clearly excluded, while all model points where $m_{\tilde t_1} > 660$ GeV and $m_{\tilde g} > 1180$ GeV remain allowed.