Tagging highly boosted top quarks

TL;DR

This paper introduces the HPTTopTagger, a novel method utilizing tracking and calorimeter data to identify highly boosted top quarks with transverse momentum above 1 TeV, improving detection at the LHC.

Contribution

The paper presents the HPTTopTagger, a new technique combining tracking and calorimeter measurements to enhance top quark tagging at very high energies.

Findings

HPTTopTagger effectively identifies top quarks with pT > 1 TeV.

Potential to discover a 3 TeV Z' boson with 300/fb data at 14 TeV LHC.

Improves upon existing methods for boosted top quark tagging.

Abstract

For highly energetic top quarks, the products of the decay t->bqq' are collimated. The 3-prong decay structure can no longer be resolved using calorimeter information alone if the particle jet separation approaches the calorimeter granularity. We propose a new method, the HPTTopTagger, that uses tracks of charged particles inside a fat jet to find top quarks with transverse momentum pT >1 TeV. The tracking information is complemented by the calorimeter measurement of the fat jet energy to eliminate the sensitivity to jet-to-jet fluctuations in the charged-to-neutral particle ratio. We show that with the HPTTopTagger, a leptophobic narrow-mass Z' boson of mass 3 TeV could be found using 300/fb of 14 TeV LHC data.