Azimuthal Angular Correlation as a Boosted Top Jet Substructure

Abstract

We propose a novel jet substructure observable of boosted tops that is related to the linear polarization of the $W$ boson in boosted top quark decay, which results in a $\cos 2\varphi$ angular correlation between the $t\to bW$ and $W\to f\overline{f^{\prime }}$ decay planes. We discuss in detail the origin of such linear polarization by applying Wigner's little group transformation. We show that the unique $\cos 2\varphi$ angular correlation only exists in the boosted regime but not in the top quark rest frame. We construct an experimental observable for such correlation based on the transverse energy deposition asymmetry in the top jet that does not require the reconstruction of $W$ decay products. The degree of this asymmetry can be used to measure the longitudinal polarization of the top quark, which is an important probe of new physics that couples to the top sector, and can discriminate a boosted top quark jet from its background events, such as QCD jets. A numerical simulation is also performed and found to agree well with the analytic prediction of the Standard Model.

arXiv comment6 pages, 3 figures. Matches the journal accepted version in PRL

References in corpus (26)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• The anti-k_t jet clustering algorithm
• FastJet user manual
• Dispelling the N^3 myth for the Kt jet-finder
• Boosted objects: a probe of beyond the Standard Model physics
• Stop Reconstruction with Tagged Tops
• The Machine Learning Landscape of Top Taggers
• Measurement of the single-top-quark t-channel cross section in pp collisions at sqrt(s) = 7 TeV
• QCD-corrected spin analysing power of jets in decays of polarized top quarks
• Spin Correlation Effects in Top Quark Pair Production at the LHC
• Performance of top-quark and $W$-boson tagging with ATLAS in Run 2 of the LHC
• Measurement of the top quark polarization and $\mathrm{t}\bar{\mathrm{t}}$ spin correlations using dilepton final states in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Quantum Interference in Jet Substructure from Spinning Gluons
• Electroweak and finite width corrections to top quark decays into transverse and longitudinal $W$-bosons
• Polarized tops from new physics: signals and observables
• Single top quark production and decay in the t-channel at next-to-leading order at the LHC
• A search for ttbar resonances in the lepton plus jets final state with ATLAS using 4.7 fb^-1 of pp collisions at sqrt(s) = 7 TeV
• Measuring the Polarization of Boosted Hadronic Tops
• Top Quark Physics
• Measurement of the cross-section and charge asymmetry of $W$ bosons produced in proton-proton collisions at $\sqrt{s}=8$ TeV with the ATLAS detector
• Top Quark Polarization As A Probe of Models with Extra Gauge Bosons
• Boosted top quark tagging and polarization measurement using machine learning
• Boosted Top quark polarization
• The fully differential top decay distribution
• Boosted Top Quarks and Jet Structure
• Jet substructures of boosted polarized hadronic tops

Cited by in corpus (2)

• Energy Correlators of Hadronically Decaying Electroweak Bosons
• Analytical Insights on Hadronic Top Quark Polarimetry