The first search for nonresonant production of Higgs boson pairs (HH) with one H decaying into four leptons and the other into a pair of b quarks is presented, using proton-proton collisions marc:recorded at a center-of-mass energy of $ \sqrt{s} $ = 13 TeV by the CMS experiment. The analyzed data correspond to an integrated luminosity of 138 fb$^{−1}$. A 95% confidence level upper limit of 32.4 is set on the signal strength modifier μ, defined as the ratio of the observed HH production rate in the $ \textrm{HH}\to {\textrm{ZZ}}^{\ast}\textrm{b}\overline{\textrm{b}}\to 4\ell \textrm{b}\overline{\textrm{b}} $ decay channel to the standard model (SM) expectation. Possible modifications of the H trilinear coupling λ$_{HHH}$ with respect to the SM value are investigated. The coupling modifier κ$_{λ}$, defined as λ$_{HHH}$ divided by its SM prediction, is constrained to be within the observed (expected) range −8.8 (−9.8) < κ$_{λ}$< 13.4 (15.0) at 95% confidence level.[graphic not available: see fulltext]
Benecke, A., Bruno, G., Bury, F., Caputo, C., David, P., Delaere, C., Donertas, I. S., Giammanco, A., Jaffel, K., Jain, S., Lemaitre, V., Mondal, K., Prisciandaro, J., Taliercio, A., Tran, T. T., Vischia, P., Wertz, S., CMS, Bethani, A., & et al. (2023). Search for nonresonant Higgs boson pair production in the four leptons plus twob jets final state in proton-proton collisions at $ \sqrt{s} $ = 13 TeV. Journal of High Energy Physics, 06. https://doi.org/10.1007/JHEP06(2023)130 (Original work published 2023)