Performance of Boosted W Boson Identification with the ATLAS Detector

This note presents the performance of a variety of techniques used to identify highly- boosted hadronically-decaying $W$ bosons. The studies presented here are divided into two parts: the first is based on Monte Carlo simulation, and the second compares the simulations to 20.3$\pm$0.6 fb$^{-1}$ of proton-–proton collisions data collected by the ATLAS detector in 2012 at $\sqrt{s} = 8$ TeV. Various tagging approaches and different grooming algorithms are compared in simulation, using a signal of large-$R$ jets containing a highly boosted $W$ boson and a background of large-$R$ jets originating from high-momentum light quarks or gluons. These techniques could also be utilised to identify hadronic decays of boosted $Z$ and Higgs bosons. A sample enriched in $t\bar{t}\to (W^+b)(W^-\bar{b}) \to (q\bar{q}b)(\mu \bar{\nu} \bar{b})$ events is used for the data comparison study. The distributions of the jet mass and substructure variables are well-described by the simulation.