Abstract
Dark matter particles, if sufficiently light, may be produced in decays of the Higgs boson. This Letter presents a statistical combination of searches for π»βinvisible decays where π» is produced according to the standard model via vector boson fusion, πβ‘(ββ’β)β’π», and π/πβ‘(had)β’π», all performed with the ATLAS detector using 36.1ββfbβ1 of πβ’π collisions at a center-of-mass energy of βπ =13ββTeV at the LHC. In combination with the results at βπ =7 and 8 TeV, an exclusion limit on the π» βinvisible branching ratio of 0.26β’(0.1β’7+0.07β0.05) at 95% confidence level is observed (expected).