"TChiHH expected mass limit curve" of "Search for higgsinos decaying to two Higgs bosons and missing transverse momentum in proton-proton collisions at $\sqrt{s}$ = 13 TeV"

Results are presented from a search for physics beyond the standard model in proton-proton collisions at $\sqrt{s}=13$ TeV in channels with two Higgs bosons, each decaying via the process H$\to b\overline{b}$, and large missing transverse momentum. The search uses a data sample corresponding to an integrated luminosity of 137 fb$^{-1}$ collected by the CMS experiment at the CERN LHC. 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. 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 ($\widetilde{\chi}^0_1$) that in turn decays to a massless goldstino and a Higgs boson, $\widetilde{\chi}^0_1$ masses in the range 175 to 1025 GeV are excluded at 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 GeV are excluded.

本研究呈现了一项搜寻结果，该搜寻利用欧洲核子研究中心（CERN）大型强子对撞机（Large Hadron Collider, LHC）紧凑型缪子线圈（Compact Muon Solenoid, CMS）实验采集的、对应积分亮度为137 fb⁻¹的质子-质子碰撞数据样本，针对质心系能量$sqrt{s}=13$ TeV下，双希格斯玻色子（Higgs boson）末态道（每个希格斯玻色子通过衰变道$ ext{H} o boverline{b}$衰变）且伴随大横向缺失动量的超出标准模型（Standard Model）新物理展开。本次搜寻的理论动机源自超对称（Supersymmetry）模型，这类模型预言中性微子（neutralino）的产生——中性微子是电弱规范玻色子与希格斯玻色子的中性超伴子。信号区域内观测到的事例产额与标准模型本底的预期结果一致。本研究基于简化超对称模型对结果进行诠释：对于近简并希格斯微子（higgsino）的电弱产生过程，每个希格斯微子的衰变链均会产生$widetilde{chi}^0_1$，后者进一步衰变为无质量金微子（goldstino）与希格斯玻色子；在95%置信度下，$widetilde{chi}^0_1$质量处于175 GeV至1025 GeV区间的参数空间被排除。对于通过质量略轻的$widetilde{chi}^0_2$衰变为希格斯玻色子与轻$widetilde{chi}^0_1$的胶微子（gluino）对的强产生过程，质量低于2330 GeV的胶微子参数空间被排除。