The simplest of them all: $$ t\overline{t}{W}^{\pm } $$ at NLO accuracy in QCD

We present results of a computation of NLO QCD corrections to the production of an off-shell top-antitop pair in association with an off-shell W+ boson in proton-proton collisions. As the calculation is based on the full matrix elements for the process $$ \mathrm{pp}\to {\mathrm{e}}^{+}{v}_{\mathrm{e}}{\mu}^{-}{\overline{v}}_{\mu }{\tau}^{+}{v}_{\tau}\mathrm{b}\overline{\mathrm{b}} $$ pp → e + v e μ − v ¯ μ τ + v τ b b ¯ , all off-shell, spin-correlation, and interference effects are included. The NLO QCD corrections are about 20% for the integrated cross-section. Using a dynamical scale, the corrections to most distributions are at the same level, while some distributions show much larger K-factors in suppressed regions of phase space. We have performed a second calculation based on a double-pole approximation. While the corresponding results agree with the full calculation within few per cent for integrated cross-sections, the discrepancy can reach 10% and more in regions of phase space that are not dominated by top-antitop production. As a consequence, on-shell calculations should only be trusted to this level of accuracy.

“…The specific final state we consider, the scale choices we analyse, and the SM input parameters differ from those of ref. [36]. However, we have reproduced the results of ref.…”

Section: Jhep11(2020)069supporting

confidence: 89%

“…However, we have reproduced the results of ref. [36] using the same setup employed therein, finding very good agreement both at the integrated and at the differential level.…”

Section: Jhep11(2020)069supporting

confidence: 53%

Section: Jhep11(2020)069mentioning

confidence: 99%

Section: Validationmentioning

confidence: 99%

Section: Validationmentioning

confidence: 99%

See 3 more Smart Citations

NLO QCD corrections to off-shell $$ \mathrm{t}\overline{\mathrm{t}}{\mathrm{W}}^{\pm } $$ production at the LHC

Denner

Pelliccioli

2020

Probing new physics with charge asymmetries in 2 same-sign leptons plus jets final states at the LHC

Arganda,

Da Rold,

Juste

et al. 2024

We study the impact of new physics models in the charge asymmetry defined for LHC final states consisting of two same-sign leptons (2SSl, with l = e, μ) plus jets (Njets ≥ 2), with a center-of-mass energy of $$ \sqrt{s} $$ s = 13 TeV, where the main SM contribution is $$ t\overline{t}W $$ t t ¯ W production. Concretely, we consider three different new physics sources for the charge asymmetries: a heavy neutral scalar/pseudoscalar arising from the general two Higgs doublet model, an effective theory with dimension-6 four-quark operators, and a simplified R-parity-violating supersymmetric model with electroweakino production (higgsino-like or wino-like). We propose measuring the charge asymmetries differentially with respect to several kinematic observables, and inclusively/exclusively with the number of b-tagged jets in the final state (Nb ≥ {1, 2, 3}). Results are compared with the SM prediction using the χ2 criteria, expressing sensitivity in terms of the normal Gaussian significance. We show that some of the proposed new physics scenarios can be probed at the LHC even for the already recorded integrated luminosity of 139 fb−1. Finally, we also estimate the prospects for the potential LHC sensitivity to the considered new physics models in its high-luminosity phase.

The present and future of four top operators

Banelli

Salvioni

Serra

et al. 2021

We study the phenomenology of a strongly-interacting top quark at future hadron and lepton colliders, showing that the characteristic four-top contact operators give rise to the most significant effects. We demonstrate the extraordinary potential of a 100 TeV proton-proton collider to directly test such non-standard interactions in four-top production, a process that we thoroughly analyze in the same-sign dilepton and trilepton channels, and explore in the fully hadronic channel. Furthermore, high-energy electron-positron colliders, such as CLIC or the ILC, are shown to exhibit an indirect yet remarkable sensitivity to four-top operators, since these constitute, via renormalization group evolution, the leading new-physics deformations in top-quark pair production. We investigate the impact of our results on the parameter space of composite Higgs models with a strongly-coupled (right-handed) top quark, finding that four-top probes provide the best sensitivity on the compositeness scale at the future energy frontier. In addition, we investigate mild yet persisting LHC excesses in multilepton plus jets final states, showing that they can be consistently described in the effective field theory of such a new-physics scenario.