Resolving Boosted Jets with XCone

TL;DR

XCone is a versatile jet algorithm that seamlessly transitions between resolved and boosted regimes, enabling consistent analysis of hadronic resonance decays across different kinematic conditions.

Contribution

The paper introduces XCone, an exclusive cone jet algorithm that maintains a fixed number of jets, unifying resolved and boosted analysis strategies.

Findings

XCone effectively reconstructs dijet resonances across kinematic regimes.

XCone accurately identifies Higgs decays to bottom quarks.

XCone successfully analyzes all-hadronic top pair events.

Abstract

We show how the recently proposed XCone jet algorithm smoothly interpolates between resolved and boosted kinematics. When using standard jet algorithms to reconstruct the decays of hadronic resonances like top quarks and Higgs bosons, one typically needs separate analysis strategies to handle the resolved regime of well-separated jets and the boosted regime of fat jets with substructure. XCone, by contrast, is an exclusive cone jet algorithm that always returns a fixed number of jets, so jet regions remain resolved even when (sub)jets are overlapping in the boosted regime. In this paper, we perform three LHC case studies---dijet resonances, Higgs decays to bottom quarks, and all-hadronic top pairs---that demonstrate the physics applications of XCone over a wide kinematic range.