Search for higgsinos in channels with two Higgs bosons and missing transverse momentum in proton-proton collisions at $\sqrt{s}=13\,\text{TeV}$

Results are presented from a search for physics beyond the standard model in proton-proton collisions at $\sqrt{s}=13\,\text{TeV}$ in final states containing two Higgs bosons, each decaying via the process $\text{H}\rightarrow\mathrm{b\overline{b}}$, and large missing transverse momentum. The search uses a data sample accumulated by the CMS experiment at the CERN LHC corresponding to an integrated luminosity of $137\,\text{fb}^{-1}$. The search is motivated by models of supersymmetry that predict the production of neutralinos, the neutral partners of the electroweak gauge and Higgs bosons. The observed event yields in the signal regions are found to be consistent with the standard model background expectations based on control regions in the data. The results are interpreted using simplified models of supersymmetry. For the electroweak production of nearly degenerate higgsinos, each of whose decay chains yields a neutralino state $\widetilde{\chi}^0_1$ that in turn decays to a massless goldstino and a Higgs boson, $\widetilde{\chi}^0_1$ masses in the range 175 to $1025\,\text{GeV}$ are excluded at the 95\% confidence level. For the strong production of gluino pairs decaying via a slightly lighter $\widetilde{\chi}^0_2$ to H and a light $\widetilde{\chi}^0_1$, gluino masses below $2330\,\text{GeV}$ are excluded.