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.
