Boosted Top quark polarization

Abstract

In top quark production, the polarization of top quarks, decided by the chiral structure of couplings, is likely to be modified in the presence of any new physics contribution to the production. Hence the same is a good discriminator for those new physics models wherein the couplings have a chiral structure different than that in the Standard Model (SM). In this note we construct probes of the polarization of a top quark decaying hadronically, using easily accessible kinematic variables such as the energy fraction or angular correlations of the decay products. Tagging the boosted top quark using the usual jet sub structure technique we study robustness of these observables for a benchmark process, $W^{\prime }\to tb$. We demonstrate that the energy fraction of b-jet in the laboratory frame and a new angular variable, constructed by us in the top rest frame, are both very powerful tools to discriminate between the left and right polarized top quarks. Based on the polarization sensitive angular variables, we construct asymmetries which reflect the polarization. We study the efficiency of these variables for two new physics processes where which give rise to boosted top quarks: (i) decay of the top squark in the context of supersymmetry searches, and (ii) decays of the Kaluza-Klein(KK) graviton and KK gluon, in Randall Sundrum(RS) model. Remarkably, it is found that the asymmetry can vary over a wide range about +20\% to -20\%. The dependence of asymmetry on top quark couplings of the new particles present in these models beyond the SM (BSM) is also investigated in detail.

arXiv comment19 pages, 12 figures, Substantially revised text, results remain unchanged. Added few references. To be published in Physical Review D

References in corpus (60)

• A Large Mass Hierarchy from a Small Extra Dimension
• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• An Introduction to PYTHIA 8.2
• FastJet user manual
• FeynRules 2.0 - A complete toolbox for tree-level phenomenology
• Better Jet Clustering Algorithms
• Bulk Fields and Supersymmetry in a Slice of AdS
• Jet substructure as a new Higgs search channel at the LHC
• Neutrino masses and mixings in non-factorizable geometry
• Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV
• Top-tagging: A Method for Identifying Boosted Hadronic Tops
• Gauge bosons in a five-dimensional theory with localized gravity
• Fat Jets for a Light Higgs
• Stop Reconstruction with Tagged Tops
• Angular Correlations in Top Quark Pair Production and Decay at Hadron Colliders
• QCD-corrected spin analysing power of jets in decays of polarized top quarks
• Top Tagging
• Measurements of $b$-jet tagging efficiency with the ATLAS detector using $t\bar{t}$ events at $\sqrt{s}=13$ TeV
• Measurement of Spin Correlation in Top-Antitop Quark Events and Search for Top Squark Pair Production in pp Collisions at $\sqrt{s}=8$ TeV Using the ATLAS Detector
• Fully differential W' production and decay at next-to-leading order in QCD
• Single Top Quark Production at the LHC: Understanding Spin
• Polarisation in Sfermion Decays: Determining \tanβand Trilinear Couplings
• Lepton distribution as a probe of new physics in production and decay of the t quark and its polarization
• Polarized Tops from Stop Decays at the LHC
• Evidence for spin correlation in ttbar production
• On measurement of top polarization as a probe of $t\bar{t}$ production mechanisms at the LHC
• QCD Corrections to Scalar Quark Decays
• Polarized tops from new physics: signals and observables
• A New Twist on Top Quark Spin Correlations
• Single top quark production and decay in the t-channel at next-to-leading order at the LHC
• Maximizing the spin correlation of top quark pairs produced at the LHC
• Measuring the Polarization of Boosted Hadronic Tops
• Measurement of ttbar Spin Correlation in ppbar Collisions Using the CDF II Detector at the Tevatron
• Boosted Semileptonic Tops in Stop Decays
• Top Quark Physics
• Search for resonant $\mathrm{t}\overline{\mathrm{t}}$ production in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Measurements of t t-bar spin correlations and top quark polarization using dilepton final states in pp collisions at sqrt(s) = 8 TeV
• Decoupling of Anomalous Top-Quark-Decay Vertices in Angular Distribution of Secondary Particles
• A Comprehensive Framework for Studying $W^{\prime }$ and $Z^{\prime }$ Bosons at Hadron Colliders with Automated Jet Veto Resummation
• Angular Distribution of Leptons in General ttbar Production and Decay
• Top Polarization in Stop Production at the LHC
• Search for $W^{\prime }\to tb$ decays in the hadronic final state using pp collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Model independent reach for W-prime bosons at the LHC
• Top-Quark Physics: Status and Prospects
• Top Polarization and Stop Mixing from Boosted Jet Substructure
• Distinguishing Di-jet Resonances at the LHC
• A new tagger for hadronically decaying heavy particles at the LHC
• Better Hadronic Top Quark Polarimetry
• A Signal for a Theory of Flavor at the LHC
• Probing anomalous $Wtb$ couplings at the LHC in single top quark production through $t$-channel
• Probing the CP properties of top Yukawa coupling at an $e^{+}{e}^{-}$ collider
• Identification of High-Momentum Top Quarks, Higgs Bosons, and W and Z Bosons Using Boosted Event Shapes
• Single Top Production as a Probe of Heavy Resonances
• Polarization of top produced in particle decays in an arbitrary frame
• Decays of polarized top quarks to lepton, neutrino and jets at NLO QCD
• Jet substructures of boosted polarized top quarks
• Jet substructures of boosted polarized hadronic tops
• LHC Searches for Top-philic Kaluza-Klein Graviton

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• Two-Higgs-Doublet Model with Soft CP-violation Confronting Electric Dipole Moments and Colliders
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• Azimuthal Angular Correlation as a Boosted Top Jet Substructure
• Searching for Heavy Charged Higgs Bosons through Top Quark Polarization
• Analytical Insights on Hadronic Top Quark Polarimetry
• Jet Substructure Probe on Scalar Leptoquark Models via Top Polarization
• Tagging a Boosted Top quark with a $\tau$ final state