The simplest of them all: $$ t\overline{t}{W}^{\pm } $$ at NLO accuracy in QCD
Autor: | Huan-Yu Bi, Giuseppe Bevilacqua, Manfred Kraus, Malgorzata Worek, H. B. Hartanto |
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Rok vydání: | 2020 |
Předmět: |
Quantum chromodynamics
Physics Quark Nuclear and High Energy Physics Top quark Particle physics Overline 010308 nuclear & particles physics High Energy Physics::Phenomenology Propagator QCD Phenomenology 01 natural sciences Factorization NLO Computations 0103 physical sciences Higgs boson lcsh:QC770-798 lcsh:Nuclear and particle physics. Atomic energy. Radioactivity High Energy Physics::Experiment Matrix element 010306 general physics |
Zdroj: | Journal of High Energy Physics Journal of High Energy Physics, Vol 2020, Iss 8, Pp 1-33 (2020) |
ISSN: | 1029-8479 |
Popis: | Recent measurements of the pp → t t ¯ W ± $$ t\overline{t}{W}^{\pm } $$ process in multi-lepton final states, as performed by the ATLAS collaboration in the context of the Higgs boson studies in the t t ¯ H $$ t\overline{t}H $$ channel, have shown discrepancies between theoretical predictions and experimental data. Such discrepancies have been observed both in the overall normalisation as well as in the modelling of the t t ¯ W ± $$ t\overline{t}{W}^{\pm } $$ process. With the goal of understanding and resolving the modelling issues within the SM t t ¯ W ± $$ t\overline{t}{W}^{\pm } $$ process we report on the state-of-the-art NLO QCD computation for this process. Specifically, we calculate higher-order corrections to the e + ν e μ − ν ¯ μ e + ν e b b ¯ $$ {e}^{+}{\nu}_e{\mu}^{-}{\overline{\nu}}_{\mu }{e}^{+}{\nu}_eb\overline{b} $$ and e − ν ¯ e μ + ν μ e − ν ¯ e b b ¯ $$ {e}^{-}{\overline{\nu}}_e{\mu}^{+}{\nu}_{\mu }{e}^{-}{\overline{\nu}}_eb\overline{b} $$ final state at the LHC with s $$ \sqrt{s} $$ = 13 TeV. In the computation off-shell top quarks are described by Breit-Wigner propagators, furthermore, double-, single- as well as non-resonant top-quark contributions along with all interference effects are consistently incorporated at the matrix element level. Results at NLO QCD accuracy are presented in the form of fiducial integrated and differential cross sections for two selected renormalisation and factorisation scale choices and three different PDF sets. The impact of the top quark off-shell effects on the t t ¯ W ± $$ t\overline{t}{W}^{\pm } $$ cross section is also examined by an explicit comparison to the narrow-width approximation. |
Databáze: | OpenAIRE |
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