Status of invisible Higgs decays

• Published in: Physics letters. B Vol. 723; no. 4-5; pp. 340 - 347
• Main Authors: Bélanger, G., Dumont, B., Ellwanger, U., Gunion, J.F., Kraml, S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25-06-2013; Elsevier
• Subjects: Bosons; Confidence intervals; Couplings; Decay; Decay rate; High Energy Physics - Phenomenology; Mathematical analysis; Physics; Searching; Vectors (mathematics)
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2013.05.024

We analyze the extent to which the LHC and Tevatron results as of the end of 2012 constrain invisible (or undetected) decays of the Higgs boson-like state at ∼125 GeV. To this end we perform global fits for several cases: (1) a Higgs boson with Standard Model (SM) couplings but additional invisible decay modes; (2) SM couplings to fermions and vector bosons, but allowing for additional new particles modifying the effective Higgs couplings to gluons and photons; (3) no new particles in the loops but tree-level Higgs couplings to the up-quarks, down-quarks and vector bosons, relative to the SM, treated as free parameters. We find that in the three cases invisible decay rates of 23%, 61%, 88%, respectively, are consistent with current data at 95% confidence level (CL). Limiting the coupling to vector bosons, CV, to CV⩽1 in case (3) reduces the allowed invisible branching ratio to 56% at 95% CL. Requiring in addition that the Higgs couplings to quarks have the same sign as in the SM, an invisible rate of up to 36% is allowed at 95% CL. We also discuss direct probes of invisible Higgs decays, as well as the interplay with dark matter searches.