"Likelihood, TChiHH at 300, 1" 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.本文报道了一项针对超出标准模型（Standard Model）物理的搜寻结果，该研究基于质心系能量$sqrt{s}=13$ TeV的质子-质子碰撞数据，研究的末态道包含两个希格斯玻色子（Higgs bosons），每个希格斯玻色子均通过$H o boverline{b}$过程衰变，且伴随大横向缺失动量（missing transverse momentum）。本次搜寻使用了欧洲核子研究中心（CERN）大型强子对撞机（LHC）上的CMS实验（CMS）采集的、积分亮度（integrated luminosity）为137 fb⁻¹的数据样本。本次搜寻的理论动机来自超对称（supersymmetry）模型，这类模型预言了中性微子（neutralinos）的产生，而中性微子是电弱规范玻色子（electroweak gauge bosons）与希格斯玻色子的中性伴随粒子。信号区域内观测到的事例产额（event yields）与标准模型本底预期相符。本次结果基于超对称简化模型（simplified models of supersymmetry）进行诠释。针对近简并希格斯微子（higgsinos）的电弱产生过程，其每条衰变链（decay chains）均会产生一个中性微子$widetilde{chi}^0_1$，该中性微子随后会衰变为无质量金斯廷诺（goldstino）与一个希格斯玻色子；在此框架下，质量介于175 GeV至1025 GeV之间的$widetilde{chi}^0_1$在95%置信水平（confidence level）下被排除。对于通过质量略轻的$widetilde{chi}^0_2$衰变为希格斯玻色子与轻中性微子$widetilde{chi}^0_1$的胶微子（gluino）对的强产生过程，质量低于2330 GeV的胶微子在该框架下被排除。