Aaboud, M, Aad, G, Abbott, B, Abdinov, O, Abeloos, B, Abhayasinghe, D K, Abidi, S H, AbouZeid, O S, Abraham, N L, Abramoqicz, H, Allbrooke, B M M, Asquith, L, Cerri, A, Chavez Barajas, C A, De Santo, A, Jones, S D, Lerner, G, Miano, F, Salvatore, F, Santoyo Castillo, I, Shaw, K, Suruliz, K, Sutton, M R, Tresoldi, F, Trovato, F, Vivarelli, I, Winkels, E, Winston, O J and The Atlas Collaboration, (2018) Observation of Higgs boson production in association with a top quark pair at the LHC with the ATLAS detector. Physics Letters B, 784. pp. 173-191. ISSN 0370-2693

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Abstract

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 b¯ b, W W ∗, τ +τ −, γγ , and Z Z∗, 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.) +110 −100 (syst.) fb, in agreement with the Standard Model prediction.

Item Type:	Article
Schools and Departments:	School of Mathematical and Physical Sciences > Physics and Astronomy
Research Centres and Groups:	Experimental Particle Physics Research Group
Related URLs:	Organisation
Depositing User:	Lily Asquith
Date Deposited:	12 Oct 2018 13:22
Last Modified:	04 Feb 2021 13:22
URI:	http://sro.sussex.ac.uk/id/eprint/79448

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