%0 Journal Article
%T Search for top-quark decays t -> Hq with 36 fb(-1) of pp collision data at root s=13 TeV with the ATLAS detector
%A ATLAS Collaboration (Aaboud, M. et al
%A Alvarez Piqueras, D.
%A Aparisi Pozo, J. A.
%A Bailey, A. J.
%A Barranco Navarro, L.
%A Cabrera Urban, S.
%A Castillo, F. L.
%A Castillo Gimenez, V.
%A Cerda Alberich, L.
%A Costa, M. J.
%A Escobar, C.
%A Estrada Pastor, O.
%A Ferrer, A.
%A Fiorini, L.
%A Fullana Torregrosa, E.
%A Fuster, J.
%A Garcia, C.
%A Garcia Navarro, J. E.
%A Gonzalez de la Hoz, S.
%A Higon-Rodriguez, E.
%A Jimenez Pena, J.
%A Lacasta, C.
%A Lozano Bahilo, J. J.
%A Madaffari, D.
%A Mamuzic, J.
%A Marti-Garcia, S.
%A Melini, D.
%A Miñano, M.
%A Mitsou, V. A.
%A Rodriguez Bosca, S.
%A Rodriguez Rodriguez, D.
%A Ruiz-Martinez, A.
%A Salt, J.
%A Santra, A.
%A Soldevila, U.
%A Sanchez, J.
%A Valero, A.
%A Valls Ferrer, J. A.
%A Vos, M.
%J Journal of High Energy Physics
%D 2019
%V 05
%N 5
%I Springer
%@ 1029-8479
%G English
%F ATLASCollaborationAaboud_etal2019
%O WOS:000468948900001
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=4033), last updated on Wed, 12 Jun 2019 15:56:45 +0000
%X A search for flavour-changing neutral current decays of a top quark into an up-type quark (q = u, c) and the Standard Model Higgs boson, t Hq, is presented. The search is based on a dataset of pp collisions at = 13 TeV recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider and corresponding to an integrated luminosity of 36.1 fb(-1). Two complementary analyses are performed to search for top-quark pair events in which one top quark decays into Wb and the other top quark decays into Hq, and target the Hbb and H (+-) decay modes, respectively. The high multiplicity of b-quark jets, or the presence of hadronically decaying -leptons, is exploited in the two analyses respectively. Multivariate techniques are used to separate the signal from the background, which is dominated by top-quark pair production. No significant excess of events above the background expectation is found, and 95% CL upper limits on the t Hq branching ratios are derived. The combination of these searches with ATLAS searches in diphoton and multilepton final states yields observed (expected) 95% CL upper limits on the t Hc and t Hu branching ratios of 1.1 x 10(-3) (8.3 x 10(-4)) and 1.2 x 10(-3) (8.3 x 10(-4)), respectively. The corresponding combined observed (expected) upper limits on the |(tcH)| and |(tuH)| couplings are 0.064 (0.055) and 0.066 (0.055), respectively.
%K Hadron-Hadron scattering (experiments)
%K Rare decay
%K Top physics
%R 10.1007/JHEP05(2019)123
%U https://arxiv.org/abs/1812.11568
%U https://doi.org/10.1007/JHEP05(2019)123
%P 123-67pp