Search for rare Higgs boson decays with mesons at the HL-LHC

Rare decays of the Higgs boson via quarkonium mesons ${Q}$ are promising laboratories to search for physics beyond the standard model (BSM). The decay channels of interest are $\gamma${Q}, {Z}{Q}, or {QQ}. BSM physics might alter Yukawa couplings to quarks, possibly resulting in higher decay rates than predicted by the standard model. Decays of the Higgs boson into a {Z} boson and a $J/\psi$ meson are searched for in four-lepton final states with the CMS detector at the LHC. In addition, Higgs decays into pairs of $\Upsilon$ mesons are studied. This analysis uses these two Higgs decays to benchmark the $95\%$ CL upper limit reach with the CMS detector at the HL-LHC.