Projections for HH measurements in the bbZZ(4l) final state with the CMS experiment at the HL-LHC

Prospects for the study of Higgs boson pair (HH) production in the HH → b$\bar{b}$4l (l = e, $\mu$) channel are studied in the context of the High-Luminosity LHC. The analysis is performed using a parametric simulation of the Phase-2 CMS detector response provided by the Delphes software and assuming an average of 200 proton-proton collisions per bunch crossing at a center-of-mass energy of 14TeV. Assuming a projected integrated luminosity of 3000 fb$^{−1}$, the expected significance for the nonresonant standard model (SM) HH signal is 0.37 σ; a 95% confidence level (CL) upper limit on its cross section is set to 6.6 times the SM prediction. The statistical combination of five decay channels ($b$$\bar{b}$, $b$$\bar{b}$, $b$$\bar{b}$$\gamma$$\gamma$, $b$$\bar{b}$WW, $b$$\bar{b}$ZZ) results in an expected significance for the SM HH signal of 2.6 σ and an expected 68% and 95% CL intervals for the Higgs self-coupling modifier κλ = λ$HHH$/λ$_{HHH}^{SM}$ of [0.35, 1.9] and [−0.18, 3.6], respectively.