Pulling the Higgs and top needles from the jet stack with feature extended supervised tagging

Abstract

Jet tagging has become an essential tool for new physics searches at the high-energy frontier. For jets that contain energetic charged leptons we introduce Feature Extended Supervised Tagging (FEST) which, in addition to jet substructure, considers the features of the charged lepton within the jet. With this method we build dedicated taggers to discriminate among boosted H→ ℓνqq¯ , t→ ℓνb, and QCD jets (with ℓ an electron or muon). The taggers have an impressive performance, allowing for overall light jet rejection factors of 10 4- 10 5, for top quark/Higgs boson efficiencies of 0.5. The taggers are also excellent in the discrimination of Higgs bosons from top quarks and vice versa, for example rejecting top quarks by factors of 100–300 for Higgs boson efficiencies of 0.5. We demonstrate the potential of these taggers to improve the sensitivity to new physics by using as example a search for a new Z′ boson decaying into ZH, in the fully-hadronic final state.