Speaker
Description
We present the first search for "soft unclustered energy patterns" (SUEPs) described by an isotropic production of many soft particles. SUEPs are a potential signature of some Hidden Valley models invoked to explain dark matter, and which can be produced at the LHC via a heavy scalar mediator. It was previously expected that such events would be rejected by conventional collider triggers and reconstruction; however, using custom data samples augmented by storing track-level information, and by targeting events where the scalar mediator recoils against initial-state radiation, this search is uniquely able to reconstruct large track clusters that are associated with the SUEP signature. The large QCD background is estimated utilizing a novel data-driven background prediction method which is shown to accurately describe data. This search achieves sensitivity across a broad range of mediator masses for the first time, where the track multiplicity is high.
