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Search for heavy Majorana or Dirac neutrinos and right-handed $W$ gauge bosons in final states with two charged leptons and two jets at $\sqrt{s}$ = 13 TeV with the ATLAS detector

ArXiv 1809.11105 (2018)

Constraints on off-shell Higgs boson production and the Higgs boson total width in ZZ → 4ℓ and ZZ → 2ℓ2ν final states with the ATLAS detector

Physics Letters B Elsevier 786 (2018) 223-244

Authors:

M Aaboud, G Aad, B Abbott, Luca Ambroz, Giacomo Artoni, Moritz Backes, Alan Barr, Lydia Beresford, Daniela Bortoletto, Jonathan Burr, Amanda Cooper-Sarkar, James Frost, Elizabeth Gallas, F Guili, Claire Gwenlan, Christopher Hays, B Todd Huffman, Cigdem Issever, Jesse Liu, Luigi Marchese, Koichi Nagai, Michael Nelson, Richard Nickerson, Nurfikri Norjoharuddeen, Santiago Paredes Saenz

Abstract:

A measurement of off-shell Higgs boson production in the and decay channels, where ℓ stands for either an electron or a muon, is performed using data from proton–proton collisions at a centre-of-mass energy of TeV. The data were collected by the ATLAS experiment in 2015 and 2016 at the Large Hadron Collider, and they correspond to an integrated luminosity of . An observed (expected) upper limit on the off-shell Higgs signal strength, defined as the event yield normalised to the Standard Model prediction, of 3.8 (3.4) is obtained at 95% confidence level (CL). Assuming the ratio of the Higgs boson couplings to the Standard Model predictions is independent of the momentum transfer of the Higgs production mechanism considered in the analysis, a combination with the on-shell signal-strength measurements yields an observed (expected) 95% CL upper limit on the Higgs boson total width of 14.4 (15.2) MeV.

Measurement of photon-jet transverse momentum correlations in 5.02 TeV Pb+Pb and $pp$ collisions with ATLAS

ArXiv 1809.0728 (2018)

Search for invisible Higgs boson decays in vector boson fusion at $\sqrt{s} = 13$ TeV with the ATLAS detector

ArXiv 1809.06682 (2018)

Observation of H→bb¯ decays and VH production with the ATLAS detector

Physics Letters B Elsevier 786 (2018) 59-86

Authors:

M Aaboud, G Aad, B Abbott, Luca Ambroz, Giacomo Artoni, Moritz Backes, Alan J Barr, Lydia Beresford, Daniela Bortoletto, Jonathan Burr, Amanda M Cooper-Sarkar, James A Frost, Elizabeth J Gallas, Francesco Giuli, Claire Gwenlan, Christopher Hays, B Todd Huffman, Jesse KK Liu, Luigi Marchese, Koichi Nagai, Michael E Nelson, Richard B Nickerson, Nurfikri Norjoharuddeen, Santiago R Paredes Saenz, Elisabeth Schopf, Abhishek Sharma, Ian PJ Shipsey, Beojan Stanislaus, Cecilia Tosciri, Jeffrey C-L Tseng, Georg HA Viehhauser, Luigi Vigani, Anthony R Weidberg, Gabija Zemaityte, Miha Zgubic, Et al.

Abstract:

A search for the decay of the Standard Model Higgs boson into a bb¯ pair when produced in association with a W or Z boson is performed with the ATLAS detector. The data, corresponding to an integrated luminosity of 79.8fb−1 were collected in proton–proton collisions during Run 2 of the Large Hadron Collider at a centre-of-mass energy of 13TeV. For a Higgs boson mass of 125GeV, an excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.9 (4.3) standard deviations. A combination with the results from other searches in Run 1 and in Run 2 for the Higgs boson in the bb¯ decay mode is performed, which yields an observed (expected) significance of 5.4 (5.5) standard deviations, thus providing direct observation of the Higgs boson decay into b-quarks. The ratio of the measured event yield for a Higgs boson decaying into bb¯ to the Standard Model expectation is 1.01±0.12(stat.)−0.15+0.16(syst.). Additionally, a combination of Run 2 results searching for the Higgs boson produced in association with a vector boson yields an observed (expected) significance of 5.3 (4.8) standard deviations.