"Efficiency, TChiHH" 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.

本研究报道了在质心系碰撞能量$sqrt{s}=13$ TeV的质子-质子碰撞中，针对双希格斯玻色子（Higgs boson）末态（每个希格斯玻色子均通过$H o boverline{b}$衰变道衰变）且伴随大横向缺失动量的物理道，开展的超出标准模型（Standard Model, SM）物理的搜寻结果。本次搜寻所用的数据样本，由欧洲核子研究组织（Conseil Européen pour la Recherche Nucléaire, CERN）大型强子对撞机（Large Hadron Collider, LHC）上的紧凑型缪子线圈（Compact Muon Solenoid, CMS）实验采集，对应积分亮度为137 fb⁻¹。
本次搜寻的理论动机来自超对称性（supersymmetry）模型，该模型预言中性微子（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伴粒子。观测得到的信号区域内的事件产额与标准模型本底预期一致。
本结果基于超对称简化模型进行诠释：对于近简并希格斯微子（higgsino）的电弱产生过程，其每条衰变链均产生最轻中性微子（$widetilde{chi}^0_1$），后者进一步衰变为无质量金斯廷诺（goldstino）与希格斯玻色子，在95%置信度下，排除了质量处于175 GeV至1025 GeV区间内的$widetilde{chi}^0_1$；对于通过略轻的次轻中性微子（$widetilde{chi}^0_2$）衰变至希格斯玻色子与最轻中性微子的胶微子（gluino）对的强产生过程，排除了质量低于2330 GeV的胶微子。