The Higgs coupling to charm quarks (and bottom quarks, and gluons)
Abstract
The SM Higgs boson is expected to decay to c ̄c with a branching ratio of about 3%. This decay will be extremely difficult to isolate and measure at LHC, but is directly accessible at FCC- ee if an efficient c-tagging algorithm, able to disentangle c ̄c decays from other copious hadronic Higgs boson decays (bb ̄ and gg, and to a lesser extent, ZZstar and WWstar) with high purity, can be designed. An ideal (100% efficient and 100% pure) tagging algorithm would yield a measurement of σZH × BR(H → c ̄c) with a precision better than 1%. Starting from the related experience developed at LHC and other e+e− collider projects, and with the help of the latest machine-learning technologies, such an algorithm will be developed, first with fast simulation, and then in the full context of the constraints from the interaction region and detector layout. The impact of the interaction-region and detector design (beam pipe radius, vertexing, vertex mass determination, tracker material, …) on the precision σZH × BR(H → c ̄c) measurement will be studied. As a by-product, similar studies for the H → bb ̄ and H → gg decays will be conducted as well. The need for calibration data at the Z pole will be estimated (frequency, number of events).
Contact
Loukas Gouskos Loukas.Gouskos@cern.ch
Michele Selvaggi Michele.Selvaggi@cern.ch
People
- Giovanni Marchiori (LPNHE)
- E. Ploerer, K. Gautam (Brussels), F. Blekman (DESY), A. Ilg (Zuerich)
Talks
- Review of flavour tagging algorithms at pp+ee and plans L. Gouskos and M. Selvaggi, talk at the FCC-ee physics meeting, July 2, 2020
- Jet flavor tagging for FCC-ee L. Gouskos and M. Selvaggi, talk at the Physics Performance meeting, Sep 21, 2020
- Update on jet flavour tagging using ParticleNet L. Gouskos and M. Selvaggi, talk at the FCC-ee physics performance meeting, Oct. 19, 2020
- Flavour tagging and application to H to cc L. Gouskos and M. Selvaggi, talk at the 4th FCC Physics and Experiments workshop, Nov 13, 2020
- status report on Flavour Tagging, FCC week, June 2022 talk by K. Gautam
- status report on Higgs ouplings, FCC week, June 2022 talk by M. Selvaggi
Bibliography
- ParticleNet: Jet Tagging via Particle Clouds H. Qu and L. Gouskos, Phys. Rev. D 101, 056019 (2020)
- Measurements of decay branching fractions of H → bb/cc/gg in associated (ee/mumu)H production at the CEPC Y. Bai et al., 2020