The Higgs Sector and Fine-Tuning in the pMSSM

TL;DR

This paper analyzes the phenomenological MSSM in light of the 125 GeV Higgs discovery, exploring Higgs properties, decay modes, fine-tuning, and models with low fine-tuning, highlighting challenges in detecting light stops and gauginos.

Contribution

It provides a detailed study of Higgs phenomenology and fine-tuning in the pMSSM, identifying models with low fine-tuning and complex decay patterns.

Findings

Many models have Higgs masses and couplings consistent with experiments.

Strong correlations found between Higgs decay final states.

Low fine-tuning models feature light stops and gauginos with complex decays.

Abstract

The recent discovery of a 125 GeV Higgs, as well as the lack of any positive findings in searches for supersymmetry, has renewed interest in both the supersymmetric Higgs sector and fine-tuning. Here, we continue our study of the phenomenological MSSM (pMSSM), discussing the light Higgs and fine-tuning within the context of two sets of previously generated pMSSM models. We find an abundance of models with experimentally-favored Higgs masses and couplings. We investigate the decay modes of the light Higgs in these models, finding strong correlations between many final states. We then examine the degree of fine-tuning, considering contributions from each of the pMSSM parameters at up to next-to-leading-log order. In particular, we examine the fine-tuning implications for our model sets that arise from the discovery of a 125 GeV Higgs. Finally, we investigate a small subset of models with low fine-tuning and a light Higgs near 125 GeV, describing the common features of such models. We generically find a light stop and bottom with complex decay patterns into a set of light electroweak gauginos, which will make their discovery more challenging and may require novel search techniques.