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Search for $$t\bar{t}H/A \rightarrow t\bar{t}t\bar{t}$$ production in proton–proton collisions at $$\sqrt{s}=13$$ $$\text {TeV}$$ with the ATLAS detector

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Search for $$t\bar{t}H/A \rightarrow t\bar{t}t\bar{t}$$ production in proton–proton collisions at $$\sqrt{s}=13$$ $$\text {TeV}$$ with the ATLAS detector. / The ATLAS collaboration.
In: European Physical Journal C: Particles and Fields, Vol. 85, No. 5, 573, 26.05.2025.

Research output: Contribution to Journal/Magazine › Journal article › peer-review

Harvard

The ATLAS collaboration 2025, 'Search for $$t\bar{t}H/A \rightarrow t\bar{t}t\bar{t}$$ production in proton–proton collisions at $$\sqrt{s}=13$$ $$\text {TeV}$$ with the ATLAS detector', European Physical Journal C: Particles and Fields, vol. 85, no. 5, 573. https://doi.org/10.1140/epjc/s10052-025-14041-z

APA

The ATLAS collaboration (2025). Search for $$t\bar{t}H/A \rightarrow t\bar{t}t\bar{t}$$ production in proton–proton collisions at $$\sqrt{s}=13$$ $$\text {TeV}$$ with the ATLAS detector. European Physical Journal C: Particles and Fields, 85(5), Article 573. https://doi.org/10.1140/epjc/s10052-025-14041-z

Vancouver

The ATLAS collaboration. Search for $$t\bar{t}H/A \rightarrow t\bar{t}t\bar{t}$$ production in proton–proton collisions at $$\sqrt{s}=13$$ $$\text {TeV}$$ with the ATLAS detector. European Physical Journal C: Particles and Fields. 2025 May 26;85(5):573. doi: 10.1140/epjc/s10052-025-14041-z

Author

The ATLAS collaboration. / Search for $$t\bar{t}H/A \rightarrow t\bar{t}t\bar{t}$$ production in proton–proton collisions at $$\sqrt{s}=13$$ $$\text {TeV}$$ with the ATLAS detector. In: European Physical Journal C: Particles and Fields. 2025 ; Vol. 85, No. 5.

Bibtex

@article{33300de6da2c4258be741a5315595519,
title = "Search for $$t\bar{t}H/A \rightarrow t\bar{t}t\bar{t}$$ production in proton{\^a}€“proton collisions at $$\sqrt{s}=13$$ $$\text {TeV}$$ with the ATLAS detector",
abstract = "A search is presented for a heavy scalar (H) or pseudo-scalar (A) predicted by the two-Higgs-doublet models, where the H/A is produced in association with a top-quark pair $$(t\bar{t}H/A),$$ ( t t {\^A}¯ H / A ) , and with the H/A decaying into a $$t\bar{t}$$ t t {\^A}¯ pair. The full LHC Run 2 proton{\^a}€“proton collision data collected by the ATLAS experiment is used, corresponding to an integrated luminosity of $$139~\text {fb}^{-1}.$$ 139 fb - 1 . Events are selected requiring exactly one or two opposite-charge electrons or muons. Data-driven corrections are applied to improve the modelling of the $$t\bar{t}$$ t t {\^A}¯ +jets background in the regime with high jet and b-jet multiplicities. These include a novel multi-dimensional kinematic reweighting based on a neural network trained using data and simulations. An H/A-mass parameterised graph neural network is trained to optimise the signal-to-background discrimination. In combination with the previous search performed by the ATLAS Collaboration in the multilepton final state, the observed upper limits on the $$t\bar{t}H/A \rightarrow t\bar{t}t\bar{t}$$ t t {\^A}¯ H / A {\^a}†{\textquoteright} t t {\^A}¯ t t {\^A}¯ production cross-section at 95% confidence level range between 14 fb and 5.0 fb for an H/A with mass between 400 $$\text {GeV}$$ GeV and 1000 $$\text {GeV}$$ GeV , respectively. Assuming that both the H and A contribute to the $$t\bar{t}t\bar{t}$$ t t {\^A}¯ t t {\^A}¯ cross-section, $$\tan \beta $$ tan {\^I}² values below 1.7 or 0.7 are excluded for a mass of 400 $$\text {GeV}$$ GeV or 1000 $$\text {GeV}$$ GeV , respectively. The results are also used to constrain a model predicting the pair production of a colour-octet scalar, with the scalar decaying into a $$t\bar{t}$$ t t {\^A}¯ pair.",
author = "{The ATLAS collaboration} and Hanadi Ali and Zainab Alsolami and A.E. Barton and G. Borissov and E.V. Bouhova-Thacker and Ruby Ferguson and James Ferrando and H. Fox and Alina Hagan and R.C.W. Henderson and R.W.L. Jones and V. Kartvelishvili and P.A. Love and Marshall, {Emma J.} and L. Meng and D. Muenstermann and N. Ribaric and Elliot Sampson and M. Smizanska and S. Spinali and A.M. Wharton",
year = "2025",
month = may,
day = "26",
doi = "10.1140/epjc/s10052-025-14041-z",
language = "English",
volume = "85",
journal = "European Physical Journal C: Particles and Fields",
issn = "1434-6044",
publisher = "SPRINGER",
number = "5",

}

RIS

TY - JOUR

T1 - Search for $$t\bar{t}H/A \rightarrow t\bar{t}t\bar{t}$$ production in proton–proton collisions at $$\sqrt{s}=13$$ $$\text {TeV}$$ with the ATLAS detector

AU - The ATLAS collaboration

AU - Ali, Hanadi

AU - Alsolami, Zainab

AU - Barton, A.E.

AU - Borissov, G.

AU - Bouhova-Thacker, E.V.

AU - Ferguson, Ruby

AU - Ferrando, James

AU - Fox, H.

AU - Hagan, Alina

AU - Henderson, R.C.W.

AU - Jones, R.W.L.

AU - Kartvelishvili, V.

AU - Love, P.A.

AU - Marshall, Emma J.

AU - Meng, L.

AU - Muenstermann, D.

AU - Ribaric, N.

AU - Sampson, Elliot

AU - Smizanska, M.

AU - Spinali, S.

AU - Wharton, A.M.

PY - 2025/5/26

Y1 - 2025/5/26

N2 - A search is presented for a heavy scalar (H) or pseudo-scalar (A) predicted by the two-Higgs-doublet models, where the H/A is produced in association with a top-quark pair $$(t\bar{t}H/A),$$ ( t t ¯ H / A ) , and with the H/A decaying into a $$t\bar{t}$$ t t ¯ pair. The full LHC Run 2 proton–proton collision data collected by the ATLAS experiment is used, corresponding to an integrated luminosity of $$139~\text {fb}^{-1}.$$ 139 fb - 1 . Events are selected requiring exactly one or two opposite-charge electrons or muons. Data-driven corrections are applied to improve the modelling of the $$t\bar{t}$$ t t ¯ +jets background in the regime with high jet and b-jet multiplicities. These include a novel multi-dimensional kinematic reweighting based on a neural network trained using data and simulations. An H/A-mass parameterised graph neural network is trained to optimise the signal-to-background discrimination. In combination with the previous search performed by the ATLAS Collaboration in the multilepton final state, the observed upper limits on the $$t\bar{t}H/A \rightarrow t\bar{t}t\bar{t}$$ t t ¯ H / A → t t ¯ t t ¯ production cross-section at 95% confidence level range between 14 fb and 5.0 fb for an H/A with mass between 400 $$\text {GeV}$$ GeV and 1000 $$\text {GeV}$$ GeV , respectively. Assuming that both the H and A contribute to the $$t\bar{t}t\bar{t}$$ t t ¯ t t ¯ cross-section, $$\tan \beta $$ tan β values below 1.7 or 0.7 are excluded for a mass of 400 $$\text {GeV}$$ GeV or 1000 $$\text {GeV}$$ GeV , respectively. The results are also used to constrain a model predicting the pair production of a colour-octet scalar, with the scalar decaying into a $$t\bar{t}$$ t t ¯ pair.

AB - A search is presented for a heavy scalar (H) or pseudo-scalar (A) predicted by the two-Higgs-doublet models, where the H/A is produced in association with a top-quark pair $$(t\bar{t}H/A),$$ ( t t ¯ H / A ) , and with the H/A decaying into a $$t\bar{t}$$ t t ¯ pair. The full LHC Run 2 proton–proton collision data collected by the ATLAS experiment is used, corresponding to an integrated luminosity of $$139~\text {fb}^{-1}.$$ 139 fb - 1 . Events are selected requiring exactly one or two opposite-charge electrons or muons. Data-driven corrections are applied to improve the modelling of the $$t\bar{t}$$ t t ¯ +jets background in the regime with high jet and b-jet multiplicities. These include a novel multi-dimensional kinematic reweighting based on a neural network trained using data and simulations. An H/A-mass parameterised graph neural network is trained to optimise the signal-to-background discrimination. In combination with the previous search performed by the ATLAS Collaboration in the multilepton final state, the observed upper limits on the $$t\bar{t}H/A \rightarrow t\bar{t}t\bar{t}$$ t t ¯ H / A → t t ¯ t t ¯ production cross-section at 95% confidence level range between 14 fb and 5.0 fb for an H/A with mass between 400 $$\text {GeV}$$ GeV and 1000 $$\text {GeV}$$ GeV , respectively. Assuming that both the H and A contribute to the $$t\bar{t}t\bar{t}$$ t t ¯ t t ¯ cross-section, $$\tan \beta $$ tan β values below 1.7 or 0.7 are excluded for a mass of 400 $$\text {GeV}$$ GeV or 1000 $$\text {GeV}$$ GeV , respectively. The results are also used to constrain a model predicting the pair production of a colour-octet scalar, with the scalar decaying into a $$t\bar{t}$$ t t ¯ pair.

U2 - 10.1140/epjc/s10052-025-14041-z

DO - 10.1140/epjc/s10052-025-14041-z

M3 - Journal article

VL - 85

JO - European Physical Journal C: Particles and Fields

JF - European Physical Journal C: Particles and Fields

SN - 1434-6044

IS - 5

M1 - 573

ER -