Observation of Higgs boson production in association with a top quark pair at the LHC with the ATLAS detector

Summary, in English

The observation of Higgs boson production in association with a top quark pair (tt¯H), based on the analysis of proton–proton collision data at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider, is presented. Using data corresponding to integrated luminosities of up to 79.8 fb−1, and considering Higgs boson decays into bb¯, WW⁎, τ+τ−, γγ, and ZZ⁎, the observed significance is 5.8 standard deviations, compared to an expectation of 4.9 standard deviations. Combined with the tt¯H searches using a dataset corresponding to integrated luminosities of 4.5 fb−1 at 7 TeV and 20.3 fb−1 at 8 TeV, the observed (expected) significance is 6.3 (5.1) standard deviations. Assuming Standard Model branching fractions, the total tt¯H production cross section at 13 TeV is measured to be 670 ± 90 (stat.) −100 +110 (syst.) fb, in agreement with the Standard Model prediction. © 2018 The Author(s)

• Author: M Aaboud; Torsten Åkesson; Simona Bocchetta; Eric Corrigan; Caterina Doglioni; Kristian Gregersen; Eva Brottmann Hansen; Vincent Hedberg; Göran Jarlskog; Charles Kalderon; Edgar Kellermann; Balazs Konya; Else Lytken; Katja Mankinen; Ulf Mjörnmark; Ruth Pöttgen; Trine Poulsen; Oxana Smirnova
• Department/s: Particle and nuclear physics; eSSENCE: The e-Science Collaboration
• Publishing year: 2018
• Language: English
• Pages: 173-191
• Publication/Series: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
• Volume: 784
• Links: http://dx.doi.org/10.1016/j.physletb.2018.07.035
• Document type: Journal article
• Publisher: Elsevier
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 0370-2693