The invisible Higgs branching fraction
Abstract
The Higgs factory, with over one million Higgs bosons produced at √s ∼ 240 and 365GeV, can give access to Higgs decays with branching ratios of a fraction of a per mil. For example, in the Standard Model, the Higgs boson decays invisibly only through the H → ZZ → νν ̄νν ̄ process, with a branching fraction of about 10−3. The rate for invisible decays of the Higgs boson may be significantly enhanced in the context of several BSM scenarios, including those in which the Higgs boson acts as a portal to dark matter (DM). Preliminary studies of the invisible decay channel at FCC-ee have already been performed in the HZ channel with Z → l+l−, and will need to be ascertained with realistic detector simulation. The study is more challenging with hadronic Z decays, for which the performance needs to be quantified. The requirements on the detector design (hadronic mass resolution, hadronic recoil-mass resolutions, maybe b-tagging performance) to approach the ultimate statistical sensitivity on the invisible branching fraction will be studied, in the context of the constraints from the full interaction region layout (in particular, with realistic beam energy spread).
Bibliography
- Prospective Studies for LEP3 with the CMS Detector P. Azzi et al, arXiv:1208.1662 [hep-ex]
- Study the effect of beam energy spread and detector resolution on the search for Higgs boson decays to invisible particles at a future e+ e− circular collider O. Cerri et al, Eur. Phys. J. C 77 (2017) 116,
Contact
Andy Mehta (amehta@cern.ch) and Nikolaos Rompotis (nikolaos.rompotis@cern.ch), Liverpool
Talks
Higgs to invisible at FCC-ee status report by A. Mehta, “Liverpool” FCC Physics workshop, Feb 2022