CMS-PAS-HIG-22-011

CMS-PAS-HIG-22-011
Search for ZZ and ZH production in the $ \rm{b}\bar{\rm{b}}\rm{b}\bar{\rm{b}} $ final state using proton-proton collisions at $ \sqrt{s}= $ 13 TeV
CMS Collaboration
4 December 2023

Abstract: A search for ZZ and ZH production in the $ \mathrm{b}\bar{\mathrm{b}}\mathrm{b}\bar{\mathrm{b}} $ final state is presented. The search uses an event sample of proton-proton collisions corresponding to an integrated luminosity of 133 fb$ ^{-1} $ at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. This analysis introduces several novel techniques for deriving and validating the data-driven background model using synthetic data sets, derived from the hemisphere-mixing technique. A multi-class multivariate classifier customized for the $ \mathrm{b}\bar{\mathrm{b}}\mathrm{b}\bar{\mathrm{b}} $ final state is developed to both extract the signal and derive the background model. The data are found to be consistent, within uncertainties, with the standard model (SM) predictions. The observed (expected) upper limit at 95% confidence level corresponds to 3.8 (3.8) and 5.0 (2.9) times the SM prediction for the ZZ and ZH production cross sections, respectively. The ZZ and ZH $ \rightarrow \mathrm{b}\bar{\mathrm{b}}\mathrm{b}\bar{\mathrm{b}} $ processes share the experimental challenges of the HH $ \rightarrow \mathrm{b}\bar{\mathrm{b}}\mathrm{b}\bar{\mathrm{b}} $ analysis. The novel techniques developed and demonstrated in the ZZ and ZH search are used to analyze the HH $ \rightarrow \mathrm{b}\bar{\mathrm{b}}\mathrm{b}\bar{\mathrm{b}} $ background. The ZZ, ZH, and HH $ \rightarrow \mathrm{b}\bar{\mathrm{b}}\mathrm{b}\bar{\mathrm{b}} $ expected sensitivities are extrapolated to an integrated luminosity of 3000 $ \mathrm{fb}^{-1} $.
Links: CDS record (PDF) ; CADI line (restricted) ; These preliminary results are superseded in this paper, Submitted to EPJC. The superseded preliminary plots can be found here.

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