Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector

Rimoldi, Marco; Mullier, Geoffrey; Miucci, Antonio; Merlassino, Claudia; Haug, Sigve; Weber, Michael; Meloni, Federico; Beck, Hans Peter; Ereditato, Antonio (2018). Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector. Physical review. D - particles, fields, gravitation, and cosmology, 97(7) American Physical Society 10.1103/PhysRevD.97.072003

[img]
Preview
Text
PhysRevD.97.072003.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (1MB) | Preview

A search for the associated production of the Higgs boson with a top quark pair (tt̅H) is reported. The search is performed in multilepton final states using a data set corresponding to an integrated luminosity of 36.1 fb⁻¹ of proton-proton collision data recorded by the ATLAS experiment at a center-of-mass energy √s = 13 TeV at the Large Hadron Collider. Higgs boson decays to WW*, ττ, and ZZ* are targeted. Seven final states, categorized by the number and flavor of charged-lepton candidates, are examined for the presence of the Standard Model Higgs boson with a mass of 125 GeV and a pair of top quarks. An excess of events over the expected background from Standard Model processes is found with an observed significance of 4.1 standard deviations, compared to an expectation of 2.8 standard deviations. The bestfit for the tt̅H production cross section is σ(tt̅H) = 790 +230 −210 fb, in agreement with the Standard Model prediction of 507 +35 −50 fb. The combination of this result with other tt̅H searches from the ATLAS experiment using the Higgs boson decay modes to bb̅, γγ and ZZ* → 4ℓ, has an observed significance of 4.2 standard deviations, compared to an expectation of 3.8 standard deviations. This provides evidence for the tt̅H production mode.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Laboratory for High Energy Physics (LHEP)

UniBE Contributor:

Haug, Sigve; Weber, Michael and Beck, Hans Peter

Subjects:

500 Science > 530 Physics

ISSN:

1550-7998

Publisher:

American Physical Society

Language:

English

Submitter:

BORIS Import LHEP

Date Deposited:

26 Jun 2019 11:06

Last Modified:

29 Jan 2021 10:45

Publisher DOI:

10.1103/PhysRevD.97.072003

Additional Information:

Kollaboration - Es sind nur die Berner Autoren namentlich erwaehnt

BORIS DOI:

10.7892/boris.129080

URI:

https://boris.unibe.ch/id/eprint/129080

Actions (login required)

Edit item Edit item
Provide Feedback