Study of ZZ and ZH production in the bb$\tau \tau$ final state and search for high-mass spin-0 and spin-1 resonances in proton-proton collisions at $\sqrt{s}$ = 13 TeV

Abstract

A study of the production of pairs of Z bosons (ZZ) and of the associated production of a Z boson and a Higgs boson (ZH) in final states containing two b quarks and two tau leptons (bb$\tau \tau$) is presented. The analysis is based on proton-proton collisions collected at $\sqrt{s}$ = 13 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 fb${}^{-1}$. The nonresonant analysis targets the standard model ZZ and ZH processes in the bb$\tau \tau$ final state, motivated by the prominent role of this channel in searches for nonresonant Higgs boson pair production. The resonant searches target physics beyond the standard model, probing heavy spin-0 resonances X that decay into ZZ and spin-1 resonances Z' that decay into ZH, with masses in the 0.2$-$5 and 0.5$-$6 TeV ranges, respectively. Upper limits at 95% confidence level are set on the product of production rate and branching fraction $\sigma$(X)$\mathcal{B}$(X $\to$ ZZ), ranging from 300 pb to 24 fb, and $\sigma$(Z')$\mathcal{B}$(Z' $\to$ ZH), ranging from 0.4 pb to 12 fb. These are the first measurements to probe the ZZ/ZH $\to$ bb$\tau \tau$ processes. No deviation from standard model expectations is observed.

This version has an updated author list. Submitted to the Journal of High Energy Physics. All figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/B2G-25-004 (CMS Public Pages)