Quantum information observables in LHC top quark pair production are modified by SMEFT dimension-6 operators in ways that depend on their CP properties, offering a complementary probe beyond standard observables.
Pinning down electroweak dipole operators of the top quark
4 Pith papers cite this work. Polarity classification is still indexing.
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abstract
We consider hadronic top quark pair production and pair production in association with a photon or a $Z$ boson to probe electroweak dipole couplings in $t\bar{b}W$, $t\bar{t}\gamma$ and $t\bar{t}Z$ interactions. We demonstrate how measurements of these processes at the 13 TeV LHC can be combined to disentangle and constrain anomalous dipole operators. The construction of cross section ratios allows us to significantly reduce various uncertainties and exploit orthogonal sensitivity between the $t\bar{t}\gamma$ and $t\bar{t}Z$ couplings. In addition, we show that angular correlations in $t\bar{t}$ production can be used to constrain the remaining $t\bar{b}W$ dipole operator. Our approach yields excellent sensitivity to the anomalous couplings and can be a further step towards precise and direct measurements of the top quark electroweak interactions.
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Computes the ratio of ttgamma/tt cross sections at LHC Run II with NLO QCD including off-shell effects, quantifying reduced theoretical uncertainties from correlations.
Analytic expressions for one-loop helicity amplitudes in ttj and ttγ production are derived to O(ε²) as linear combinations of pentagon functions with rational coefficients in momentum-twistor variables, obtained via differential equations solved numerically by generalized power series expansion.
CMS reports fiducial and differential ttγ cross sections plus ttγ/tt ratios at 13 TeV that agree with Standard Model expectations within uncertainties.
citing papers explorer
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Quantumness of top quark pairs produced at LHC within SMEFT framework
Quantum information observables in LHC top quark pair production are modified by SMEFT dimension-6 operators in ways that depend on their CP properties, offering a complementary probe beyond standard observables.
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On the ratio of $t\bar{t}\gamma$ and $t\bar{t}$ cross sections at the LHC
Computes the ratio of ttgamma/tt cross sections at LHC Run II with NLO QCD including off-shell effects, quantifying reduced theoretical uncertainties from correlations.
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One-loop amplitudes for $t\bar{t}j$ and $t\bar{t}\gamma$ productions at the LHC through $\mathcal{O}(\epsilon^2)$
Analytic expressions for one-loop helicity amplitudes in ttj and ttγ production are derived to O(ε²) as linear combinations of pentagon functions with rational coefficients in momentum-twistor variables, obtained via differential equations solved numerically by generalized power series expansion.
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Inclusive and differential measurements of the $\mathrm{t\bar{t}}\gamma$ cross section and the $\mathrm{t\bar{t}}\gamma$ / $\mathrm{t\bar{t}}$ cross section ratio in proton-proton collisions at $\sqrt{s}$ = 13 TeV
CMS reports fiducial and differential ttγ cross sections plus ttγ/tt ratios at 13 TeV that agree with Standard Model expectations within uncertainties.