New NLOPS predictions for $\mathbf{t}\bar{\mathbf{t}}+\mathbf{b}$-jet production at the LHC

Abstract

Measurements of $t\bar{t}H$ production in the $H\to b\bar{b}$ channel depend in a critical way on the theoretical uncertainty associated with the irreducible $t\bar{t}+b$-jet background. In this paper, analysing the various topologies that account for $b$-jet production in association with a $t\bar{t}$ pair, we demonstrate that the process at hand is largely driven by final-state $g\to b\bar{b}$ splittings. We also show that in five-flavour simulations based on $t\bar{t}+$multi-jet merging $b$-jet production is mostly driven by the parton shower, while matrix elements play only a marginal role in the description of $g\to b\bar{b}$ splittings. Based on these observations we advocate the use of NLOPS simulations of $pp\to t\bar{t}b\bar{b}$ in the four-flavour scheme, and we present a new POWHEG generator of this kind. Predictions and uncertainties for $t\bar{t}+b$-jet observables at the 13 TeV LHC are presented both for the case of stable top quarks and with spin-correlated top decays. Besides QCD scale variations we consider also theoretical uncertainties related to the POWHEG matching method and to the parton shower modelling, with emphasis on $g\to b\bar{b}$ splittings. In general, matching and shower uncertainties turn out to be remarkably small. This is confirmed also by a tuned comparison against Sherpa+OpenLoops.

43 pages, 15 figures. Version accepted for publication in EPJC. Results unchanged. Figs. 9-10 updated

References in corpus (13)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• Event generation with SHERPA 1.1
• Reducing full one-loop amplitudes to scalar integrals at the integrand level
• NLO vector-boson production matched with shower in POWHEG
• OneLOop: for the evaluation of one-loop scalar functions
• Assault on the NLO Wishlist: pp -> tt bb
• Higgs boson production in association with top quarks in the POWHEG BOX
• Scalar one-loop 4-point integrals
• NLO QCD corrections to pp -> t anti-t b anti-b + X at the LHC
• On-the-fly reduction of open loops
• An NLO+PS generator for $t\bar{t}$ and $Wt$ production and decay including non-resonant and interference effects
• Hadroproduction of $t\bar{t}b\bar{b}$ final states at LHC: predictions at NLO accuracy matched with Parton Shower

Cited by in corpus (47)

• AtlFast3: the next generation of fast simulation in ATLAS
• Event Generators for High-Energy Physics Experiments
• Search for $\mathrm{t}\overline{\mathrm{t}}$H production in the H $\to$ $\mathrm{b}\overline{\mathrm{b}}$ decay channel with leptonic $\mathrm{t}\overline{\mathrm{t}}$ decays in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Measurements of fiducial and differential cross-sections of $t\bar{t}$ production with additional heavy-flavour jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector
• Search for a charged Higgs boson decaying into top and bottom quarks in events with electrons or muons in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Les Houches 2021: Physics at TeV Colliders: Report on the Standard Model Precision Wishlist
• Measurement of the $\mathrm{t}\bar{\mathrm{t}}\mathrm{b}\bar{\mathrm{b}}$ production cross section in the all-jet final state in pp collisions at $\sqrt{s}=$ 13 TeV
• Machine learning the Higgs boson-top quark CP phase
• Measurement of Higgs boson decay into $b$-quarks in associated production with a top-quark pair in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Measurement of the $t\bar{t}t\bar{t}$ production cross section in $pp$ collisions at $\sqrt{s}$=13 TeV with the ATLAS detector
• Lepton-pair production in association with a $b\bar{b}$ pair and the determination of the $W$ boson mass
• Multi-jet merging in a variable flavor number scheme
• $t\bar{t}b\bar{b}$ at the LHC: On the size of corrections and $b$-jet definitions
• Off-shell vs on-shell modelling of top quarks in photon associated production
• Measurement of the cross section for $\text{t}\bar{\text{t}}$ production with additional jets and b jets in pp collisions at $\sqrt{s}=$ 13 TeV
• Search for a light charged Higgs boson in $t\to H^{\pm }b$ decays, with $H^{\pm }\to cb$, in the lepton+jets final state in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Full NLO QCD corrections to off-shell ttbb production
• Top-Yukawa contributions to bbH production at the LHC
• Learning to pinpoint effective operators at the LHC: a study of the $t\bar{t}b\bar{b}$ signature
• NLO QCD predictions for $t\bar{t}b\bar{b}$ production in association with a light jet at the LHC
• A fragmentation-based study of heavy quark production
• The Role of the $t\bar{t}h$ Rest Frame in Direct Top-Quark Yukawa Coupling Measurements
• Probing the $CP$ nature of the top-Higgs Yukawa coupling in $t\bar{t}H$ and $tH$ events with $H\to b\bar{b}$ decays using the ATLAS detector at the LHC
• First measurement of the cross section for top quark pair production with additional charm jets using dileptonic final states in pp collisions at $\sqrt{s}=$ 13 TeV
• A study of additional jet activity in top quark pair production and decay at the LHC
• $t\bar{t}b\bar{b}$ at the LHC: On the size of off-shell effects and prompt $b$-jet identification
• Resonance-aware subtraction in the dipole method
• Measurement of the associated production of a top-antitop-quark pair and a Higgs boson decaying into a $b\bar{b}$ pair in $pp$ collisions at $\sqrt{s}=13$ TeV using the ATLAS detector at the LHC
• Search for a new scalar resonance in flavour-changing neutral-current top-quark decays $t\to qX$ ($q=u,c$), with $X\to b\bar{b}$, in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Search for Higgs boson pair production with one associated vector boson in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Measurement of the $\mathrm{t}\bar{\mathrm{t}}$H and tH production rates in the H $\to$ $\mathrm{b}\bar{\mathrm{b}}$ decay channel using proton-proton collision data at $\sqrt{s}$ = 13 TeV
• Search for new physics using effective field theory in 13 TeV pp collision events that contain a top quark pair and a boosted Z or Higgs boson
• Les Houches 2023 -- Physics at TeV Colliders: Report on the Standard Model Precision Wishlist
• Measurement of $t\bar{t}$ production in association with additional $b$-jets in the $e\mu$ final state in proton-proton collisions at $\sqrt{s}$=13 TeV with the ATLAS detector
• Constraint for a light charged Higgs boson and its neutral partners from top quark pairs at the LHC
• Measurement of top-quark pair production in association with charm quarks in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Search for dark mesons decaying to top and bottom quarks in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Inclusive and differential cross section measurements of $\mathrm{t}\bar{\mathrm{t}}\mathrm{b}\bar{\mathrm{b}}$ production in the lepton+jets channel at $\sqrt{s}$ = 13 TeV
• Search for $t\bar{t}H/A\to t\bar{t}t\bar{t}$ production in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Simultaneous probe of the charm and bottom quark Yukawa couplings using $\mathrm{t}\bar{\mathrm{t}}$H events
• Five-flavour scheme predictions for $t\bar{t}b\bar{b}$ at next-to-leading order accuracy
• Calibration of a soft secondary vertex tagger using proton-proton collisions at $\sqrt{s}=$13 TeV with the ATLAS detector
• Hadroproduction of four top quarks in the POWHEG BOX
• Measurements of the Cross-Section for the $t\bar{t}$ + Heavy-Flavor Production at the LHC
• Measurements of $t\bar{t}$ in association with charm quarks at 13 TeV with the ATLAS experiment
• Measurements of differential cross-sections of $WbWb$ production in the dilepton channel in $pp$ collisions at $\sqrt{s}$ = 13 TeV using the ATLAS detector
• Directly Probing the Higgs-top Coupling at High Scales