Ditau-Jet Tagging and Boosted Higgses from a Multi-TeV Resonance

Abstract

New TeV-scale physics processes at the LHC can produce Higgs bosons with substantive transverse Lorentz boost, such that the Higgs's decay products are nominally contained in a single jet. In the case of a light Higgs decaying predominantly to bb, previous studies have shown that these Higgs-jets can be identified by capitalizing on jet substructure techniques. In this work, we explore the possibility of also utilizing the subdominant but very distinctive decay h -> tau tau. To this end, we introduce the concept of a ``ditau-jet,'' or a jet consisting of two semi-collinear taus where one or both decay hadronically. We perform simple modifications to ordinary tau tagging methods to account for this configuration, and estimate tag rates of order 50% and QCD mistag rates of order 0.1%-0.01% for p_T TeV, even in the presence of pileup. We further demonstrate the feasibility of reconstructing the ditau invariant mass by using traditional MET projection techniques. Given these tools, we estimate the sensitivity of the LHC for discovery of a multi-TeV Z' decaying to Zh, utilizing both leptonic and hadronic Z decay channels. The leptonic Z channel is limited due to low statistics, but the hadronic Z channel is potentially competitive with other searches.