Spheres to jets tuning event shapes with 5d simplified models

Hidden sectors could give rise to a wide variety of events at the LHC. Confining hidden sectors are known to engender events with a small number of jets when they are weakly-coupled at high energies, and quasi-spherical soft unclustered energy patterns (SUEPs) when they are very strongly-coupled (large 't Hooft coupling) at high energies. The intermediate regime is murky, and could give rise to signals hiding from existing search strategies. While the intermediate coupling regime is not calculable, it is possible to pursue a phenomenological approach in which one creates signals that are intermediate between spherical and jetty. We propose a strategy for generating events of this type using simplified models in extra dimensions. The degree to which the event looks spherical is related to the number of decays produced near kinematic threshold. We provide an analytic understanding of how this is determined by parameters of the model. To quantify the shape of events produced with this model, we use a recently proposed observable - event isotropy - which is a better probe of the spherical regime than earlier event shape observables.

Automated summary

Hidden sectors can result in a variety of events at the LHC, ranging from events with a small number of jets to quasi-spherical soft unclustered energy patterns. The intermediate regime, where the coupling is unclear, may lead to signals that evade existing search strategies. By using simplified models in extra dimensions, events with intermediate characteristics between spherical and jetty can be generated, with the shape of the event depending on the number of decays produced near kinematic threshold. The analytic understanding and use of event isotropy as an observable provide insight into the shape of events produced in this model.