title: Probing the Higgs couplings to photons in h→4ℓ at the LHC.
abstract: We explore the sensitivity of the Higgs decay to four leptons, the so-called golden channel, to higher dimensional loop-induced couplings of the Higgs boson to ZZ, Zγ, and γγ pairs, allowing for general CP mixtures. The larger standard model tree level coupling hZ(μ)Z(μ) is the dominant "background" for the loop-induced couplings. However, this large background interferes with the smaller loop-induced couplings, enhancing the sensitivity. We perform a maximum likelihood analysis based on analytic expressions of the fully differential decay width for h→4ℓ (4ℓ≡2e2μ,4e,4μ), including all interference effects. We find that the spectral shapes induced by Higgs couplings to photons are particularly different than the hZ(μ)Z(μ) background leading to enhanced sensitivity to these couplings. We show that even if the h→γγ and h→4ℓ rates agree with that predicted by the standard model, the golden channel has the potential to probe both the CP nature as well as the overall sign of the Higgs coupling to photons well before the end of a high-luminosity LHC.
authors.affiliation: Lauritsen Laboratory for High Energy Physics, California Institute of Technology, Pasadena, California 92115, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Theoretical Physics Department, Fermilab, P.O. Box 500, Batavia, Illinois 60510, USA.
authors.forename: Roni
authors.initials: R
authors.lastname: Harnik
authors.affiliation: Laboratoire de Physique Théorique d'Orsay, UMR8627-CNRS, Université Paris-Sud, 91405 Orsay, France.
authors.forename: Roberto
authors.initials: R
authors.lastname: Vega-Morales