Tracking down hyper-boosted top quarks

TL;DR

This paper introduces a new jet tagging method for identifying hyper-boosted top quarks at future high-energy colliders, effectively discriminating them from background jets at transverse boosts up to 20 TeV.

Contribution

The paper proposes a simple, scalable jet tagging strategy combining calorimetric and track information, suitable for extremely boosted heavy particle identification at future colliders.

Findings

Efficient discrimination of top quarks from QCD jets up to 20 TeV boost.

Jet radius scaling inversely with transverse boost improves tagging performance.

Method remains effective despite high pile-up and contamination conditions.

Abstract

The identification of hadronically decaying heavy states, such as vector bosons, the Higgs, or the top quark, produced with large transverse boosts has been and will continue to be a central focus of the jet physics program at the Large Hadron Collider (LHC). At a future hadron collider working at an order-of-magnitude larger energy than the LHC, these heavy states would be easily produced with transverse boosts of several TeV. At these energies, their decay products will be separated by angular scales comparable to individual calorimeter cells, making the current jet substructure identification techniques for hadronic decay modes not directly employable. In addition, at the high energy and luminosity projected at a future hadron collider, there will be numerous sources for contamination including initial- and final-state radiation, underlying event, or pile-up which must be mitigated. We propose a simple strategy to tag such "hyper-boosted" objects that defines jets with radii that scale inversely proportional to their transverse boost and combines the standard calorimetric information with charged track-based observables. By means of a fast detector simulation, we apply it to top quark identification and demonstrate that our method efficiently discriminates hadronically decaying top quarks from light QCD jets up to transverse boosts of 20 TeV. Our results open the way to tagging heavy objects with energies in the multi-TeV range at present and future hadron colliders.