CERN Accelerating science

ATLAS Note
Report number	ATLAS-CONF-2020-008
Title	Search for invisible Higgs boson decays with vector boson fusion signatures with the ATLAS detector using an integrated luminosity of 139 fb$^{-1}$
Corporate Author(s)	The ATLAS collaboration
Collaboration	ATLAS Collaboration
Publication	2020
Imprint	17 Apr 2020
Number of pages	mult.
Note	All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CONFNOTES/ATLAS-CONF-2020-008
Subject category	Particle Physics - Experiment
Accelerator/Facility, Experiment	CERN LHC ; ATLAS
Free keywords	ATLAS ; Higgs ; Vector Boson Fusion ; Dark Matter
Abstract	A direct search for Higgs bosons that are produced via vector boson fusion and subsequently decay into invisible particles is reported.The analysis uses 139 fb$^{-1}$ of $pp$ collision data at $\sqrt{s}$ = 13 TeV recorded by the ATLAS detector at the LHC. The observed number of events are found to be in agreement with the background expectation from Standard Model processes. Assuming a 125 GeV scalar Higgs boson with a Standard Model production cross section, both the observed and expected upper limits on the branching fraction of its decay into invisible particles are derived to be 0.13 at 95$\%$ confidence level. These results are also interpreted in the context of models where the 125 GeV Higgs boson acts as a portal to dark matter, and limits are set on the scattering cross-section of weakly interacting massive particles and nucleons. The invisible decays of additional scalar bosons with masses from 50 GeV up to 1 TeV are also studied, and upper limits on the cross section times branching fraction are evaluated to be 0.97 pb for a scalar boson mass of 50 GeV, which falls with increasing mass to become 0.12 pb at a mass of 1 TeV.
Related document	superseded by: CERN-EP-2021-258

Corresponding record in: Inspire