CMS-PAS-HIG-19-012

CMS-PAS-HIG-19-012
Search for decays of the 125 GeV Higgs boson into a Z boson and a $\rho$ or $\phi$ meson
CMS Collaboration
May 2020

Abstract: The decays of the 125 GeV Higgs boson into a Z boson and a $\rho^0(770)$ or $\phi(1020)$ meson are searched for using proton-proton collision data collected by the CMS experiment at the LHC from 2016 to 2018 at $\sqrt{s}= $ 13 TeV. The analysed data set corresponds to an integrated luminosity of 137 fb$^{-1}$. Events are selected in which the Z boson decays into a pair of electrons or a pair of muons, and the $\rho$ and $\phi$ mesons decay into pairs of pions and kaons, respectively. No significant excess above the background model is observed. As different polarization states are possible for the decay products of the Z boson and $\rho$ or $\phi$ mesons, affecting the signal acceptance, scenarios in which the decays are longitudinally or transversely polarized are considered. Upper limits at the 95% confidence level on the Higgs boson branching fractions into Z$\rho$ and Z$\phi$ are determined to be 1.21-1.89% and 0.36-0.58%, respectively, where the ranges reflect the considered polarization scenarios; these values are 860-1350 and 860-1380 times larger than the respective standard model expectations. These results constitute the first experimental limits on these two decay channels.
Links: CDS record (PDF) ; inSPIRE record ; CADI line (restricted) ; These preliminary results are superseded in this paper, JHEP 11 (2020) 039. The superseded preliminary plots can be found here.

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