Search of Rare Decays of the Higgs Boson

Rare decays of the Higgs boson are promising laboratories to search for physics beyond the standard model (BSM). Such BSM physics might alter Yukawa couplings to lighter quarks or enter via loop diagrams, possibly resulting in higher decay rates than predicted by the standard model. Of particular interest are decays of the Higgs boson into a Z boson and a quarkonium state. For the first time the decay of the Higgs boson into a Z boson and Upsilon states are searched for, where the Υ(1S), Υ(2S) and Y(3S) states are combined. For these decays and decays into Z and charmonium states machine learning techniques are applied to characterize the background. A data sample of proton-proton collisions collected at a center-of-mass energy of 13 TeV with the Compact Muon Solenoid detector at the Large Hadron Collider that corresponds to an integrated luminosity of about 137 fb⁻¹ is used. I will present the searches and implications for future searches of BSM signatures at higher luminosity.