Model-independent measurement of the top quark polarisation

Abstract

We introduce a new asymmetry in the decay t -> W b -> l nu b, which is shown to be directly proportional to the polarisation of the top quark along a chosen axis, times a sum of W helicity fractions. The latter have already been precisely measured at the Tevatron and the Large Hadron Collider. Therefore, this new asymmetry can be used to obtain a model-independent measurement of the polarisation of top quarks produced in any process at hadron or lepton colliders.

LaTeX 12 pages. Discussion expanded with a new plot, references added. Final version to appear in PLB

References in corpus (24)

• Effective-Field-Theory Approach to Top-Quark Production and Decay
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Cited by in corpus (16)

• Search for anomalous Wtb couplings and flavour-changing neutral currents in t-channel single top quark production in pp collisions at sqrt(s) = 7 and 8 TeV
• Asymmetries in top quark pair production at hadron colliders
• Anomalous Top-Higgs Couplings and Top Polarisation in Single Top and Higgs Associated Production at the LHC
• Breaking down the entire W boson spin observables from its decay
• New directions for top quark polarization in the $t$-channel process
• Probing the $Wtb$ vertex structure in $t$-channel single-top-quark production and decay in $pp$ collisions at $\sqrt{\mathrm{s}}=8$ TeV with the ATLAS detector
• Single top quark production at the LHC
• Looking for bSM physics using top-quark polarization and decay-lepton kinematic asymmetries
• The fully differential top decay distribution
• Quantum coherence, top transverse polarisation and the Tevatron asymmetry $A_{FB}^{\ell }$
• Polarization of top and chargino from stop decay in natural SUSY
• A template method to measure the $t\bar{t}$ polarisation
• NLO QCD and EW corrections to off-shell $\mathrm{tZj}$ production at the LHC
• Study of Top Effective Operators at the ILC
• Probing $|V_{td}|$ in single-top production at $p{e}^{\mp }$ colliders
• Single top quark polarization at O(alpha_s) in t t-bar production at a polarized linear e^+ e^- collider