Inclusive and differential cross-sections for dilepton $$ t\overline{t} $$ production measured in $$ \sqrt{s} $$ = 13 TeV pp collisions with the ATLAS detector

Abstract

Differential and double-differential distributions of kinematic variables of leptons from decays of top-quark pairs ($$ t\overline{t} $$ t t ¯ ) are measured using the full LHC Run 2 data sample collected with the ATLAS detector. The data were collected at a pp collision energy of $$ \sqrt{s} $$ s = 13 TeV and correspond to an integrated luminosity of 140 fb−1. The measurements use events containing an oppositely charged eμ pair and b-tagged jets. The results are compared with predictions from several Monte Carlo generators. While no prediction is found to be consistent with all distributions, a better agreement with measurements of the lepton pT distributions is obtained by reweighting the $$ t\overline{t} $$ t t ¯ sample so as to reproduce the top-quark pT distribution from an NNLO calculation. The inclusive top-quark pair production cross-section is measured as well, both in a fiducial region and in the full phase-space. The total inclusive cross-section is found to be$$ {\sigma}_{t\overline{t}}=829\pm 1\ \left(\textrm{stat}\right)\pm 13\ \left(\textrm{syst}\right)\pm 8\ \left(\textrm{lumi}\right)\pm 2\ \left(\textrm{beam}\right)\ \textrm{pb}, $$ σ t t ¯ = 829 ± 1 stat ± 13 syst ± 8 lumi ± 2 beam pb , where the uncertainties are due to statistics, systematic effects, the integrated luminosity and the beam energy. This is in excellent agreement with the theoretical expectation.

Top-quark pole mass extraction at NNLO accuracy, from total, single- and double-differential cross sections for $$ t\overline{t} $$ + X production at the LHC

“…For our analysis, we use measurements of the absolute total and normalized differential inclusive tt + X cross sections 5 as a function of various top-quark related observables O i , JHEP05(2024)321 (dσ/dO i )/σ. We collect all available and up-to-date ATLAS and CMS measurements of total tt + X cross sections [43][44][45][46][47][48][49][50][51]. These are ten data points which appear on the summary plot of the total tt + X cross sections by the LHC Working Group on Top Quark Physics as of June 2023 [95].…”

“…the experimental data published in refs. [43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58]).…”

Measurement of top-quark electroweak couplings in associated top quark production with vector bosons at the ATLAS and CMS experiments

“…The biggest data sample at the LHC was collected at 13 TeV between 2016-2018 and has since been studied in great detail. A new analysis from ATLAS in the dilepton channel using the full data set of 140 fb −1 documents the most precise measurement of σ t t so far [7]. Events containing an opposite signed (OS) e ± µ ∓ pair and either one or two b jets are selected.…”

“…The final result also features the use of the jet vertex tagger to reject jets from pileup. Similar to the 13 TeV analysis by AT-LAS [7], events with one or two b jets are categorized and σ t t is measured simultaneously with the b tagging efficiency. The obtained cross section of σ t t = 850 ± 3(stat) ± 18(syst) ± 20(lumi) pb shows a small trend towards a smaller value than predicted.…”

“…6 Differential t t cross section measurements at √ s = 13 TeV Both ATLAS and CMS have recently analyzed single and multi-differential t t cross section measurements in the dileptonic channel using the full Run 2 data of 140 and 138 fb, respectively [7,14]. The ATLAS measurement is documented together with the previously discussed inclusive cross section measurements at 13 TeV and the same strategy is used.…”