MSSM dark matter measurements at the LHC without squarks and sleptons

TL;DR

This paper presents a method to predict dark matter properties in the MSSM focus point scenario at the LHC, using dilepton spectra to constrain neutralino mixing without relying on squark or slepton detection.

Contribution

It introduces a novel Bayesian technique to infer neutralino properties from dilepton spectra, improving LHC constraints without assuming detection of heavy scalar sparticles.

Findings

Accurate predictions of relic density and annihilation cross-section from dilepton spectra.

Demonstrated the effectiveness of the method in a 24-parameter MSSM model.

Enhanced LHC analysis without requiring detection of heavy scalar sparticles.

Abstract

We examine the case of neutralino dark matter in the focus point region of the MSSM, in which the scalar sparticles are too heavy to be produced at the LHC. Whilst it has been previously asserted that the LHC alone would fail to constrain the properties of the lightest neutralino for such a scenario, we find that one can obtain good predictions of astrophysical quantities such as the relic density, annihilation cross-section and direct search cross-sections by using the shape of the dilepton invariant mass spectrum to constrain neutralino mixing. We demonstrate our technique using a Bayesian analysis of the 24 parameter MSSM model space, and in the process introduce a novel way of improving the LHC results even without assumptions on which new sparticles are responsible for the kinematic features in the dilepton invariant mass distribution.