scholarly journals Measurement of the Spin Correlation in the Top Quark Pair Production using the Dilepton Events in 1.96-TeV Proton-Antiproton Collisions

2012 ◽  
Author(s):  
Kenichi Takemasa
Keyword(s):  
Pair Production ◽  
Top Quark ◽  
Spin Correlation ◽  
Proton Antiproton ◽  
Dilepton Events

SPIN CORRELATION EFFECTS IN THE HADROPRODUCTION AND DECAY OF VERY HEAVY TOP QUARK PAIRS

1989 ◽  
Vol 04 (03) ◽  
pp. 617-625 ◽  
Author(s):  
V. BARGER ◽  
J. OHNEMUS ◽  
R. J. N. PHILLIPS
Keyword(s):  
Top Quark ◽  
Spin Correlation ◽  
Weak Decay ◽  
Tree Level ◽  
Matrix Elements ◽  
Correlation Effects ◽  
Quark Pairs ◽  
Quark Spin ◽  
Dilepton Events ◽  
Top Quark Pairs

Density matrix techniques in the helicity basis allow us to write down explicitly the squared matrix elements for tree-level hadroproduction and weak decay of very heavy top quark pairs, that decay before hadronization. This treatment includes the full effects of quark spin correlation. We illustrate the effects of spin correlation on physical distributions in [Formula: see text] dilepton events, [Formula: see text], [Formula: see text], [Formula: see text], for the case mt =120 GeV at [Formula: see text], the energy of the Tevatron collider. The effects of spin correlation are quantitatively small compared to calculations that ignore them, giving corrections of order 10% or less in the physical distributions studied.

scholarly journals Probing the spin correlations of $$t{\bar{t}} $$ production at NLO QCD+EW

2021 ◽  
Vol 81 (9) ◽  
Author(s):  
Rikkert Frederix ◽  
Ioannis Tsinikos ◽  
Timea Vitos
Keyword(s):  
Pair Production ◽  
Top Quark ◽  
Correlation Coefficients ◽  
Spin Correlation ◽  
Spin Correlations ◽  
Scale Uncertainty ◽  
Narrow Width Approximation ◽  
Uncertainty Band ◽  
Fixed Order ◽  
Narrow Width

AbstractIn this work we investigate the NLO QCD+EW corrections to the top quark pair production and their effects on the spin correlation coefficients and asymmetries at fixed-order top quark pair production and LO decay in the dilepton channel, within the narrow-width approximation. The spin correlations are implicitly measured through the lepton kinematics. Moreover we study the EW effects to the leptonic differential distributions. We find that the EW corrections to the $$t {\bar{t}}$$ t t ¯ production are within the NLO QCD theoretical uncertainties for the spin correlation coefficients and the leptonic asymmetries. On the other hand, for the differential distributions we find that the EW corrections exceed the NLO QCD scale uncertainty band in the high rapidity regimes and are of the order of the NLO QCD scale uncertainty in the case of invariant mass and transverse momentum distributions.

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