Where to look for natural supersymmetry

TL;DR

This paper uses Bayesian analysis to identify prior-independent bounds on the MSSM Higgs boson mass and tan beta, providing new insights into where natural supersymmetry might be detected.

Contribution

It introduces a prior-independent upper bound on the pseudoscalar Higgs mass and tan beta in the MSSM, refining the parameter space for natural supersymmetry searches.

Findings

Upper bound on $m_A$ is about 3 TeV at 95% confidence.

Naturalness line relates $m_A$ to $m_Z$ and tan beta, reducing free parameters.

Bayesian approach emphasizes prior-independent features in supersymmetry analysis.

Abstract

Why is natural supersymmetry neither detected nor ruled-out to date? To answer this question we use the Bayesian approach where the emphasis on finding prior-independent features within broader and minimally biased frames is taken as the guiding principle. The 20-parameter minimal supersymmetric standard model (MSSM) fits to subjective naturalness indicate the existence of a prior-independent upper bound on the pseudoscalar Higgs boson mass $m_A$ as a function of $\tan \beta$, the ratio of the vacuum expectation values of the MSSM Higgs doublets. For a 30-parameter MSSM this implies that $m_A \lesssim 3$ TeV and $\tan \beta \lesssim 25$ at 95\% Bayesian confidence. Removing the contradictory subjectiveness within the electroweak fine-tuning measure leads to finding the naturalness line, $m_A \sim \frac{1}{\sqrt{2}} \, m_Z \, \tan \beta,$ that reduces by one the number of MSSM Higgs sector free parameters.