Jet substructure from dark sector showers

Joel Doss,Timothy Cohen,Marat Freytsis

doi:10.1007/jhep09(2020)118

Joel Doss, Timothy Cohen + Show 1 more

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https://doi.org/10.1007/jhep09(2020)118

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Abstract

We examine the robustness of collider phenomenology predictions for a dark sector scenario with QCD-like properties. Pair production of dark quarks at the LHC can result in a wide variety of signatures, depending on the details of the new physics model. A particularly challenging signal results when prompt production induces a parton shower that yields a high multiplicity of collimated dark hadrons with subsequent decays to Standard Model hadrons. The final states contain jets whose substructure encodes their non-QCD origin. This is a relatively subtle signature of strongly coupled beyond the Standard Model dynamics, and thus it is crucial that analyses incorporate systematic errors to account for the approximations that are being made when modeling the signal. We estimate theoretical uncertainties for a canonical substructure observable designed to be sensitive to the gauge structure of the underlying object, the two-point energy correlator {e}_2^{left(beta right)} , by computing envelopes between resummed analytic distributions and numerical results from Pythia. We explore the separability against the QCD background as the confinement scale, number of colors, number of flavors, and dark quark masses are varied. Additionally, we investigate the uncertainties inherent to modeling dark sector hadronization. Simple estimates are provided that quantify one’s ability to distinguish these dark sector jets from the overwhelming QCD background. Such a search would benefit from theory advances to improve the predictions, and the increase in statistics using the data to be collected at the high luminosity LHC.

Highlights

IntroductionSimple estimates are provided that quantify one’s ability to distinguish these dark sector jets from the overwhelming QCD background
Of particular relevance here is the idea that the dark matter could be a stable remnant of some new strong dynamics that resides in a hidden sector [4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28]
We focus on scenarios where the dark hadrons that result from a dark sector shower promptly decay back to Standard Model hadrons

Summary

Introduction

Simple estimates are provided that quantify one’s ability to distinguish these dark sector jets from the overwhelming QCD background Such a search would benefit from theory advances to improve the predictions, and the increase in statistics using the data to be collected at the high luminosity LHC. It is reasonable to assume the presence of some non-gravitational connection to the visible sector, such that the hidden sector was in thermal contact with the Standard Model at some point in the early Universe This could result from a renormalizable interaction involving the Higgs, Neutrino, and/or Hypercharge Portals [29,30,31] or could be due to the exchange of some new mediator. Since substructure is sensitive to a variety of IR effects, such as the dark hadron mass spectrum and hadronization model, our work provides an observable-driven window into the systematic issues associated with making predictions for these strongly coupled dark sector scenarios

Objectives

Conclusion