Logo del repository
  1. Home
 
Opzioni

Search for tt ̄H/A→tt ̄tt ̄ production in proton–proton collisions at s=13 TeV with the ATLAS detector

Zwalinski L.
•
Zou W.
•
Zormpa O.
altro
Aad G.
2025
  • journal article

Periodico
THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS
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 (tt ̄H/A), and with the H/A decaying into a tt ̄ pair. The full LHC Run 2 proton–proton collision data collected by the ATLAS experiment is used, corresponding to an integrated luminosity of 139fb-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 tt ̄+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 tt ̄H/A→tt ̄tt ̄ production cross-section at 95% confidence level range between 14 fb and 5.0 fb for an H/A with mass between 400 GeV and 1000 GeV, respectively. Assuming that both the H and A contribute to the tt ̄tt ̄ cross-section, tanβ values below 1.7 or 0.7 are excluded for a mass of 400 GeV or 1000 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 tt ̄ pair.
DOI
10.1140/epjc/s10052-025-14041-z
Archivio
https://hdl.handle.net/11390/1309964
info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-105009301920
https://ricerca.unityfvg.it/handle/11390/1309964
Diritti
metadata only access
google-scholar
Get Involved!
  • Source Code
  • Documentation
  • Slack Channel
Make it your own

DSpace-CRIS can be extensively configured to meet your needs. Decide which information need to be collected and available with fine-grained security. Start updating the theme to match your nstitution's web identity.

Need professional help?

The original creators of DSpace-CRIS at 4Science can take your project to the next level, get in touch!

Realizzato con Software DSpace-CRIS - Estensione mantenuta e ottimizzata da 4Science

  • Impostazioni dei cookie
  • Informativa sulla privacy
  • Accordo con l'utente finale
  • Invia il tuo Feedback