Related papers: Constraining new resonant physics with top spin po…
The degree of top polarization and strength of $t\bar{t}$ correlation are dependent on production dynamics, decay mechanism, and choice of the observables. At the LHC, measurement of the top polarization and spin correlations in $t\bar{t}$…
The top quark plays an important role in searches for physics beyond the SM, both as a dominant background and as a key signature for the signal. The most notable feature found in the top physics analyses in both ATLAS and CMS…
Both ATLAS and CMS have recently performed the first searches for a heavy new spin-0 resonance decaying into a lighter new spin-0 resonance and a $Z$ boson, where the lighter spin-0 resonance subsequently decays into $t \bar t$ pairs. These…
Measurements of $\mathrm{t\bar{t}}$ spin correlations are presented in events with top quarks produced in $\mathrm{pp}$ collisions at the LHC. The data correspond to an integrated luminosity of $36\:\mathrm{fb^{-1}}$ at…
Stringent tests on top quark production and decay mechanisms are provided by the measurement of the top quark and W boson polarization. This paper presents a detailed study of these two measurements with the ATLAS detector, in the…
Observables sensitive to top quark polarization are important for characterizing or even discovering new physics. The most powerful spin analyzer in top decay is the down-type fermion from the W, which in the case of leptonic decay allows…
We study the spin properties of top quarks produced in collisions of polarized photons in the threshold region. For a relatively heavy top quark the influence of non-perturbative effects is small and its polarization parameters can be…
The top quark decays before it hadronizes. Before its spin state can be changed in a process of strong interaction, it is directly transferred to the top quark decay products. The top quark spin can be deduced by studying angular…
Recent results of CMS at the top-antitop quark pair production threshold in the dileptonic and semileptonic decay channels are presented. The results were obtained analyzing $138~\mathrm{fb}^{-1}$ of $pp$ collision data taken at…
We present the first analysis of top spin polarizations, $t \bar t$ spin correlations, and $t \bar t$ spin entanglement at the LHC in the context of the Standard Model Effective Field Theory, that goes beyond Leading Order QCD accuracy. The…
The Large Hadron Collider has delivered exceptionally large proton-proton collision datasets at centre-of-mass energies of up to 13.6 TeV. These datasets, collected by the ATLAS and CMS detectors, enable precision tests of theoretical…
A number of top-spin observables are computed within the Standard Model (SM), at next-to-leading order in the strong and weak gauge couplings for hadronic top-quark anti-quark (ttbar) production and decay at the LHC for center-of-mass…
We investigate the prospects for spin determination of a heavy diboson resonance using angular observables. Focusing in particular on boosted fully hadronic final states, we detail both the differences in signal efficiencies and distortions…
Polarization and spin correlation measurements of top quark-antiquark ($t\bar{t}$) pairs provide tests of the standard model, but also new ways to test quantum mechanics with unstable particles at highest energies ever produced in a…
We investigate the effects of new physics scenarios containing a high mass vector resonance on top pair production at the LHC, using the polarization of the produced top. In particular we use kinematic distributions of the secondary lepton…
We attract attention to the fact that the ultimate (shot-noise-limited) polarimetric sensitivity can be enhanced by orders of magnitude leaving the photon flux incident onto the photodetector on the same low level. This opportunity is of…
We study the sensitivity of the ATLAS experiment to Wtb anomalous couplings in top pair production with semileptonic decay, pp -> t tbar -> W+ b W- bbar, with one of the W bosons decaying leptonically and the other hadronically. Several…
We compare the impact of top-quark spin polarization effects in Higgs boson production in association with top-quark pairs and in corresponding backgrounds at the LHC. Because of the spin-zero nature of the Higgs boson, one expects, in the…
Polarization and spin correlations have been explored very little for quarks other than the top. Utilizing the partial preservation of the quark's spin information in baryons in the jet produced by the quark, we examine possible analysis…
Measurements of the top quark-antiquark (t t-bar) spin correlations and the top quark polarization are presented for t t-bar pairs produced in pp collisions at sqrt(s) = 8 TeV. The data correspond to an integrated luminosity of 19.5 inverse…