Probing Higgs-portal dark matter with vector-boson fusion
Jan Heisig (Centre for Cosmology, Particle Physics and Phenomenology (CP3), Université catholique de Louvain, Chemin du Cyclotron 2, Louvain-la-Neuve, B-1348, Belgium); Michael Krämer (Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, Aachen, D-52056, Germany); Eric Madge (PRISMA+ Cluster of Excellence and Mainz Institute for Theoretical Physics, Johannes Gutenberg-Universität Mainz, Mainz, 55099, Germany); Alexander Mück (Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, Aachen, D-52056, Germany)
We constrain the Higgs-portal model employing the vector-boson fusion channel at the LHC. In particular, we include the phenomenologically interesting parameter region near the Higgs resonance, where the Higgs-boson mass is close to the threshold for dark-matter production and a running-width prescription has to be employed for the Higgs- boson propagator. Limits for the Higgs-portal coupling as a function of the dark-matter mass are derived from the CMS search for invisible Higgs-boson decays in vector-boson fusion at 13 TeV. Furthermore, we perform projections for the 14 TeV HL-LHC and the 27 TeV HE-LHC taking into account a realistic estimate of the systematic uncertainties. The respective upper limits on the invisible branching ratio of the Higgs boson reach a level of 2% and constrain perturbative Higgs-portal couplings up to dark-matter masses of about 110 GeV.
