"TChiHH-G_th" 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.

本研究展示了一项搜寻结果：在质心系能量$sqrt{s}=13$ TeV的质子-质子碰撞中，针对双希格斯玻色子（Higgs boson）末态通道——每个希格斯玻色子均通过$ ext{H} o boverline{b}$过程衰变，且伴随大横向缺失动量（missing transverse momentum）——搜寻超出标准模型（Standard Model, SM）的新物理。本次搜寻使用了紧凑缪子线圈（Compact Muon Solenoid, CMS）实验在欧洲核子研究中心（CERN, European Organization for Nuclear Research）大型强子对撞机（Large Hadron Collider, LHC）上采集的、对应积分亮度（integrated luminosity）为137 fb⁻¹的数据样本。该搜寻的理论动机来自超对称（Supersymmetry, SUSY）模型，这类模型预言了中性伴子（neutralino）的产生：中性伴子是电弱规范玻色子（electroweak gauge boson）与希格斯玻色子的中性超对称伙伴粒子。分析结果显示，信号区域内观测到的事例产额（event yield）与标准模型本底（background）的预期结果一致。本研究结果基于超对称简化模型（simplified models of supersymmetry）进行诠释。针对近简并希格斯微子（higgsino）的电弱产生过程，其每个衰变链均会产生一个最轻中性伴子（$widetilde{chi}^0_1$），该最轻中性伴子会进一步衰变为无质量金斯蒂诺（goldstino）与希格斯玻色子；在此框架下，质量介于175 GeV至1025 GeV之间的$widetilde{chi}^0_1$被以95%置信水平（confidence level）排除。针对通过质量略轻的$widetilde{chi}^0_2$衰变为希格斯玻色子与最轻中性伴子的胶微子（gluino）对的强产生过程，质量低于2330 GeV的胶微子被排除。