Theory, phenomenology, and experimental avenues for dark showers: a Snowmass 2021 report

TL;DR

This report reviews theoretical models, phenomenological signatures, and experimental strategies for detecting dark showers arising from a strongly coupled dark sector at the LHC, emphasizing new benchmarks and jet substructure techniques.

Contribution

It introduces new benchmark models, improves simulation tools like PYTHIA Hidden Valley, and proposes advanced search strategies for dark showers at the LHC.

Findings

Development of consistent physical benchmarks for dark sectors

Enhancement of jet substructure analysis techniques

Proposed search strategies for dark shower signatures

Abstract

In this work, we consider the case of a strongly coupled dark/hidden sector, which extends the Standard Model (SM) by adding an additional non-Abelian gauge group. These extensions generally contain matter fields, much like the SM quarks, and gauge fields similar to the SM gluons. We focus on the exploration of such sectors where the dark particles are produced at the LHC through a portal and undergo rapid hadronization within the dark sector before decaying back, at least in part and potentially with sizeable lifetimes, to SM particles, giving a range of possibly spectacular signatures such as emerging or semi-visible jets. Other, non-QCD-like scenarios leading to soft unclustered energy patterns or glueballs are also discussed. After a review of the theory, existing benchmarks and constraints, this work addresses how to build consistent benchmarks from the underlying physical parameters and present new developments for the PYTHIA Hidden Valley module, along with jet substructure studies. Finally, a series of improved search strategies is presented in order to pave the way for a better exploration of the dark showers at the LHC.