TY  - CONF
AU  - Amoroso, Simone
AU  - Britzger, Daniel
AU  - Kluth, Stefan
AU  - Scyboz, Ludovic
TI  - NLOPS off-shell effects in precise determinations of the top-quark mass and width at the LHC
JO  - Proceedings of Science / International School for Advanced Studies
VL  - (EPS-HEP2023)
SN  - 1824-8039
CY  - Trieste
PB  - SISSA
M1  - PUBDB-2025-02157
SP  - 313
PY  - 2024
N1  - cc-by-nc-nd
AB  - The precise measurement of the properties of the top quark are among the most important goals of the LHC. The signature o top quarks can only be measured through their decay products, which are almost exclusively a W-boson and a b-quark, and unbiased measurements of the top-quark pair production process are therefore performed in the final state of two W-bosons and two b-quarks (WWbb). However, the WWbb final state has further contributions from single-top production and even from channels without intermediate top-quarks. At next-to-leading order QCD, these channels interfere and cannot be calculated separately any more, and since the top quarks can be off their mass shell, also finite width effects become important.In this contribution, we exploit a measurement of the WWbb final state in the di-lepton decay channel from ATLAS at 13 TeV together with a next-to-leading order QCD prediction supplemented with parton shower in the Powheg-Box-Res framework (denoted 'bb4l') for a determination of the top-quark mass and its width. We evaluate the impact of using the fully off-shell calculations, and study the correlation between the top quark mass and width. For the inference, we make use of a novel analytic parameter estimation ansatz, the Linear Template Fit, which will also be introduced briefly.
T2  - 2023 European Physical Society Conference on High Energy Physics
CY  - 21 Aug 2023 - 25 Aug 2023, Hamburg (Germany)
Y2  - 21 Aug 2023 - 25 Aug 2023
M2  - Hamburg, Germany
KW  - top: mass (INSPIRE)
KW  - top: width (INSPIRE)
KW  - higher-order: 1 (INSPIRE)
KW  - width: finite (INSPIRE)
KW  - top: pair production (INSPIRE)
KW  - effect: off-shell (INSPIRE)
KW  - bottom: pair production (INSPIRE)
KW  - W W (INSPIRE)
KW  - parton: showers (INSPIRE)
KW  - quantum chromodynamics (INSPIRE)
KW  - CERN LHC Coll (INSPIRE)
KW  - signature (INSPIRE)
KW  - correlation (INSPIRE)
KW  - ATLAS (INSPIRE)
KW  - dilepton: final state (INSPIRE)
KW  - leptonic decay (INSPIRE)
LB  - PUB:(DE-HGF)16 ; PUB:(DE-HGF)8
DO  - DOI:10.22323/1.449.0313
UR  - https://bib-pubdb1.desy.de/record/632229
ER  -