Realistic simplified gaugino-higgsino models in the MSSM

TL;DR

This paper introduces realistic simplified MSSM models for light neutralinos and charginos, emphasizing proper mass spectrum and mixing matrix diagonalization to improve experimental search benchmarks at the LHC.

Contribution

It proposes a novel strategy for designing MSSM benchmark scenarios with realistic mass spectra and mixing, improving upon naive approaches.

Findings

Developed a method for realistic MSSM benchmark models

Applied parameter scans to higgsino scenarios

Discussed implications for dark matter phenomenology

Abstract

We present simplified MSSM models for light neutralinos and charginos with realistic mass spectra and realistic gaugino-higgsino mixing, that can be used in experimental searches at the LHC. The formerly used naive approach of defining mass spectra and mixing matrix elements manually and independently of each other does not yield genuine MSSM benchmarks. We suggest the use of less simplified, but realistic MSSM models, whose mass spectra and mixing matrix elements are the result of a proper matrix diagonalisation. We propose a novel strategy targeting the design of such benchmark scenarios, accounting for user-defined constraints in terms of masses and particle mixing. We apply it to the higgsino case and implement a scan in the four relevant underlying parameters {{\mu}, tan\beta, M_1, M_2} for a given set of light neutralino and chargino masses. We define a measure for the quality of the obtained benchmarks, that also includes criteria to assess the higgsino content of the resulting charginos and neutralinos. We finally discuss the distribution of the resulting models in the MSSM parameter space as well as their implications for supersymmetric dark matter phenomenology.