Two analyses searching for the production of supersymmetric particles through the electroweak interaction are presented: the chargino search, targeting the pair production of charginos decaying into W bosons and neutralinos, and the displaced track search, looking for charged tracks arising from the decays of higgsinos into pions. These searches target compressed phase spaces, where the mass difference between the next-to-lightest and lightest supersymmetric particle is relatively small. The searches use proton-proton collision data collected at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. In the chargino search, the targeted mass difference between charginos and neutralinos is close to the mass of the W boson. In such phase space, the chargino pair production is kinematically similar to the WW background, making the chargino signal experimentally challenging to be discriminated from the WW background. Machine learning techniques are adopted to separate the supersymmetric signal from the backgrounds. The results exclude chargino masses up to about 140 GeV for mass splittings down to about 100 GeV, superseding the previous results in particularly interesting regions where the chargino pair production could have hidden behind the looking-alike WW background. In the displaced track search, the mass difference between the produced sparticles and the lightest neutralinos goes down to 0.3 GeV. The experimental signature has a low momentum charged track with an origin displaced from the collision point. The results show that the analysis has the sensitivity to exclude different hypotheses for higgsino masses up to 175 GeV if no excess is observed in data. For lower masses, the larger signal cross-section allows to achieve higher significance for different mass splitting scenarios. All these signal hypotheses have not been probed by any existing analysis of LHC data.
Observation of electroweak $W^{\pm}Z$ boson pair production in association with two jets in $pp$ collisions at $\sqrt{s} =$ 13 TeV with the ATLAS detector
Dark matter interpretations of ATLAS searches for the electroweak production of supersymmetric particles in $\sqrt{s} = 8$ TeV proton-proton collisions
Measurement of the electroweak production of dijets in association with a Z-boson and distributions sensitive to vector boson fusion in proton-proton collisions at sqrt(s) = 8 TeV using the ATLAS detector
Measurement of the cross-section for electroweak production of dijets in association with a $Z$ boson in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in $\sqrt{s}$ = 13 TeV $pp$ collisions with the ATLAS detector
Search for the electroweak diboson production in association with a high-mass dijet system in semileptonic final states in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
Observation of electroweak production of a same-sign $W$ boson pair in association with two jets in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
Measurement of electroweak $Z(ν\barν)γjj$ production and limits on anomalous quartic gauge couplings in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
Fiducial and differential cross-section measurements of electroweak $Wγjj$ production in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector
Search for direct production of electroweakinos in final states with one lepton, missing transverse momentum and a Higgs boson decaying into two $b$-jets in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
本文给出了电弱伴子对产生$pp \rightarrow \tildeχ^\pm_1 \tildeχ^0_2$的研究结果，其中电荷伴子（$\tildeχ^\pm_1$）衰变为$W$玻色子和最轻的中性伴子（$\tildeχ^0_1$），而较重的中性伴子（$\tildeχ^0_2$）衰变为标准模型125 GeV的希格斯玻色子和第二个$\tildeχ^0_1$。信号的选择需要一对带有$b$标记的喷流，这些喷流与来自希格斯玻色子玻色子衰变的喷流一致，并且需要来自$W$玻色子衰变的电子或μ子，以及来自相应中微子和稳定中性伴子的缺失的横向动量。分析是基于相应的数据139 $\mathrm{fb}^{-1}$的$\sqrt{s}=13$ TeV $pp$碰撞提供的大型强子对撞机和记录的ATLAS探测器。没有统计学上的显着证据的事件超过标准模型expectations. Limits设置在简化模型中的直接生产的电弱子，假设纯维诺横截面。对于无质量的$\tildeχ^{0}_{1}$，在95%置信水平下排除高达740 GeV的$\tildeχ^{\pm}_{1}/\tildeχ^{0}_{2}$质量。
Search for anomalous electroweak production of $WW/WZ$ in association with a high-mass dijet system in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector
本文研究了矢量玻色子散射中反常的四次规范玻色子耦合。用于分析的数据对应于$\sqrt{s}=8$ TeV $pp$碰撞的$20.2$ fb $^{-1}$，并于2012年由大型强子对撞机的ATLAS实验收集。搜索寻找$WW$或$WZ$玻色子对的产生伴随着一个高质量的双喷射系统，其中一个$W$轻子衰变，一个$W$或$Z$强子衰变。强子衰变$W/Z$重建为两个小半径射流或一个大半径射流使用射流子结构技术。通过拟合双玻色子系统的横向质量，对反常四次规范玻色子耦合参数$α_4$和$α_5$进行约束，得到的95%置信区间分别为$-0.024<α_4<0.030$和$-0.028<α_5<0.033$ .
Searches for electroweak production of supersymmetric particles with compressed mass spectra in $\sqrt{s}=13$ TeV $pp$ collisions with the ATLAS detector
Search for electroweak production of charginos and sleptons decaying into final states with two leptons and missing transverse momentum in $\sqrt{s}=13$ TeV $pp$ collisions using the ATLAS detector
Search for direct stop pair production with the ATLAS detector
超对称性通过为标准模型（SM）引入超对称伙伴来扩展标准模型（SM），可以为层次问题提供一个优雅的解决方案。超对称性中最重要的参数之一是顶夸克的超对称伙伴的质量，称为停止。在LHC之前的搜索中没有停止签名的情况下，压缩停止搜索（其中停止的质量接近最轻的中性伴子的质量）变得更加重要。在压缩质谱的情况下，动量转移到停止的衰变产物可能很小，导致衰变产物的横动量只有几个GeV。因此，这些“软”物体的识别和重建可以在搜索中发挥至关重要的作用。本文介绍了用ATLAS探测器在$\sqrt{s}$ =13 TeV pp碰撞中进行压缩停止搜索的最新结果和软b强子标记技术的新进展。
Measurement of the cross-sections of the electroweak and total production of a $Z γ$ pair in association with two jets in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector
Search for direct production of electroweakinos in final states with missing transverse momentum and a Higgs boson decaying into photons in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
Search for electroweak-scale dijet resonances using trigger-level analysis with the ATLAS detector in $132$ fb$^{-1}$ of $pp$ collisions at $\sqrt{s} = 13$ TeV
EUROPEAN ORGANISATION FOR NUCLEAR RESEARCH (CERN)（欧洲核子研究组织（CERN））
Search for signatures of electroweakinos with photons, jets, and large missing transverse momentum in $\sqrt{s}=13$ TeV pp collisions with the ATLAS detector
EUROPEAN ORGANISATION FOR NUCLEAR RESEARCH (CERN)（欧洲核子研究中心（CERN））
Observation of electroweak production of two jets in association with an isolated photon and missing transverse momentum, and search for a Higgs boson decaying into invisible particles at 13 TeV with the ATLAS detector
Search for pair-produced third-generation squarks decaying via charm quarks or in compressed supersymmetric scenarios in $pp$ collisions at $\sqrt{s}=8~$TeV with the ATLAS detector
本文报道了通过直接产生第三代方子来寻找超对称性的结果，使用了2012年在LHC的ATLAS实验中记录的$\sqrt{s} = 8$ TeV质子-质子碰撞数据的$20.3$ fb $^{-1}$。基于单喷流和$c$标记事件选择的两种不同的分析策略进行优化的灵敏度直接顶部夸克对产生的衰变通道的粲夸克和最轻的中性伴（$\tilde{t}_1 \to c + \tildeχ_{1}^{0}$）在顶部夸克-中性伴质量参数空间。没有观察到超过标准模型背景预期的情况。结果被解释的上下文中的直接对生产的顶部squarks和（$m_{\tilde{t}_1}$，$m_{\tildeχ_{1}^{0}}$）参数空间中的排除限制。在95 $\%$置信水平下，任意中性伴子质量的运动学边界内，排除了质量高达约240 GeV的顶夸克。对于200 GeV的中性伴子质量，排除了高达270 GeV的顶级夸克质量。在顶夸克和最轻的中性伴子的质量几乎简并的情况下，顶夸克质量高达260 GeV被排除在外。从单喷流分析的结果也解释在压缩的情况下，顶部夸克对生产的衰变通道$\tilde{t}_1 \to b + ff^{'} + \tildeχ^{0}_{1}$和sbottom对生产与$\tilde{b}_1 \to b + \tildeχ^{0}_{1}$，导致类似的排斥近质量简并的第三代squarks和最轻的中性伴子。本…
A search for electroweak $t\bar{t}Wj$ production in multileptonic final states at $\sqrt{s} = 13$ TeV with the ATLAS detector and bounds on effective field theory operators
EUROPEAN ORGANISATION FOR NUCLEAR RESEARCH (CERN)（欧洲核子研究组织（CERN））
Electroweak diboson production in association with a high-mass dijet system in semileptonic final states from $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector
EUROPEAN ORGANISATION FOR NUCLEAR RESEARCH (CERN)（欧洲核子研究中心）
Measurement of $VH$, $H\to b\bar{b}$ production as a function of the vector-boson transverse momentum in 13 TeV $pp$ collisions with the ATLAS detector
