Characterizing dark matter at the LHC in Drell-Yan events

TL;DR

This paper explores how spectral features in LHC dileptonic events can reveal dark matter properties and mediator characteristics using simplified models, with constraints comparable to other detection methods.

Contribution

It demonstrates how invariant mass and scattering angle distributions can identify dark matter properties and mediator quantum numbers in Drell-Yan events.

Findings

Scattering angle distributions can provide strong bounds on dark matter models.

Spectral features can distinguish dark matter properties such as spin and self-conjugation.

Constraints from LHC are competitive with direct detection and jet + missing energy searches.

Abstract

Spectral features in LHC dileptonic events may signal radiative corrections coming from new degrees of freedom, notably dark matter and mediators. Using simplified models, we show how these features can reveal the fundamental properties of the dark sector, such as self-conjugation, spin and mass of dark matter, and the quantum numbers of the mediator. Distributions of both the invariant mass $m_{\ell \ell}$ and the Collins-Soper scattering angle $cos\theta_{CS}$ are studied to pinpoint these properties. We derive constraints on the models from LHC measurements of $m_{\ell \ell}$ and $cos\theta_{CS}$, which are competitive with direct detection and jets + Missing Energy searches. We find that in certain scenarios the $cos\theta_{CS}$ spectrum provides the strongest bounds, underlying the importance of scattering angle measurements for non-resonant new physics.