Searching for Confining Hidden Valleys at the LHC(b)

Abstract: We explore strategies for probing Hidden Valley scenarios exhibiting confinement. Such scenarios lead to a multiplicity of light hidden hadrons from showering processes. Their decays are typically soft and displaced, making them challenging to probe with traditional LHC searches. We show the low trigger thresholds and excellent track and vertex reconstruction at LHCb provide an ideal environment to search for such signals -- in both muonic and hadronic channels. We also explore the potential of ATLAS/CMS and discuss modifications to present searches that might make these experiments competitive with the LHCb reach. Our proposed searches can probe $Z^{\prime}$ models with dominant decays to dark sectors as well as exotic Higgs boson decays in Twin Higgs models.