LHC Searches for Dark Sector Showers

TL;DR

This paper introduces a new search strategy for dark sector showers at the LHC, focusing on semi-visible jets, and provides sensitivity projections for different portal models, highlighting the LHC's unique advantages.

Contribution

It proposes a novel search program for dark sector showers, including a simplified parametrization and targeted strategies for unexplored parameter regions at the LHC.

Findings

Sensitivity projections for various portal models.

Identification of parameter space regions not covered by existing analyses.

Highlighting the LHC's unique capability in dark matter searches.

Abstract

This paper proposes a new search program for dark sector parton showers at the Large Hadron Collider (LHC). These signatures arise in theories characterized by strong dynamics in a hidden sector, such as Hidden Valley models. A dark parton shower can be composed of both invisible dark matter particles as well as dark sector states that decay to Standard Model particles via a portal. The focus here is on the specific case of 'semi-visible jets,' jet-like collider objects where the visible states in the shower are Standard Model hadrons. We present a Simplified Model-like parametrization for the LHC observables and propose targeted search strategies for regions of parameter space that are not covered by existing analyses. Following the 'mono-$X$' literature, the portal is modeled using either an effective field theoretic contact operator approach or with one of two ultraviolet completions; sensitivity projections are provided for all three cases. We additionally highlight that the LHC has a unique advantage over direct detection experiments in the search for this class of dark matter theories.