CMS-PAS-HIG-18-025

CMS-PAS-HIG-18-025
Search for Higgs and Z boson decays to $\mathrm{J}/\psi$ or $\Upsilon$ pairs in proton-proton collisions at $\sqrt{s}=$ 13 TeV
CMS Collaboration
March 2019

Abstract: A search is presented for decays of the Higgs and Z boson to pairs of $\mathrm{J}/\psi$ or $\Upsilon(n\mathrm{S})$ ( $n=$ 1, 2, 3), with the subsequent decay of the mesons to $\mu^+\mu^-$ . The analysis uses data from proton-proton collisions with an integrated luminosity of 37.5 fb $^{-1}$ at $\sqrt{s}=$ 13 TeV collected with the CMS detector at the LHC in 2017. An observation of such a decay with this sample would indicate the presence of physics beyond the standard model. No significant excess of events is observed and 95% confidence level upper limits are placed on the branching fractions. In the $\mathrm{J}/\psi$ pair final state the limits are 1.8 $\times 10^{-3}$ and 2.2 $\times 10^{-6}$ for the Higgs and Z boson, respectively, while in the combined $\Upsilon(n\mathrm{S})$ pair final states the limits are 1.4 $\times 10^{-3}$ and 1.5 $\times 10^{-6}$ , respectively. The $\mathrm{J}/\psi$ and $\Upsilon(n\mathrm{S})$ mesons from the Higgs and Z decay are assumed unpolarized. With longitudinally polarized $\mathrm{J}/\psi$ and $\Upsilon$ mesons in the Higgs and Z decay the upper limits reduce by about 22-29%, while with transversely polarized mesons the decay limits increase by about 10-13%.
Links: CDS record (PDF) ; inSPIRE record ; CADI line (restricted) ; These preliminary results are superseded in this paper, PLB 797 (2019) 134811. The superseded preliminary plots can be found here.

CMS Publications