从限制黑暗部门的暗物质颗粒的生产可能导致许多新颖的实验签名。根据理论的细节,质子 - 质子碰撞中的黑暗夸克生产可能导致颗粒的半衰期:黑暗强度的准直喷雾,其中颗粒碰撞器实验只有一些。实验签名的特征在于,具有与喷射器的可见部件相结合的重建缺失的动量。这种复杂的拓扑对检测器效率低下和错误重建敏感,从而产生人为缺失的势头。通过这项工作,我们提出了一种信号不可知的策略来拒绝普通喷射,并通过异常检测技术鉴定半衰期喷射。具有喷射子结构变量的深度神经自动化器网络作为输入,证明了对分析异常喷射的非常有用。该研究重点介绍了半意射流签名;然而,该技术可以适用于任何新的物理模型,该模型预测来自非SM粒子的喷射器的签名。
translated by 谷歌翻译
我们描述了作为黑暗机器倡议和LES Houches 2019年物理学研讨会进行的数据挑战的结果。挑战的目标是使用无监督机器学习算法检测LHC新物理学的信号。首先,我们提出了如何实现异常分数以在LHC搜索中定义独立于模型的信号区域。我们定义并描述了一个大型基准数据集,由> 10亿美元的Muton-Proton碰撞,其中包含> 10亿美元的模拟LHC事件组成。然后,我们在数据挑战的背景下审查了各种异常检测和密度估计算法,我们在一组现实分析环境中测量了它们的性能。我们绘制了一些有用的结论,可以帮助开发无监督的新物理搜索在LHC的第三次运行期间,并为我们的基准数据集提供用于HTTPS://www.phenomldata.org的未来研究。重现分析的代码在https://github.com/bostdiek/darkmachines-unsupervisedChallenge提供。
translated by 谷歌翻译
无监督的异常检测对于未来在大型数据集中搜索稀有现象的分析可能至关重要,例如在LHC收集的。为此,我们介绍了一个受到物理启发的变量自动编码器(VAE)体系结构,该体系结构在LHC奥运会机器学习挑战数据集中竞争性和稳健性。我们证明了如何将某些物理可观察物直接嵌入VAE潜在空间中,同时使分类器显然是不可知的,可以帮助识别和表征测得的光谱中的特征,这是由于数据集中存在异常而引起的。
translated by 谷歌翻译
AutoEncoders在异常检测中具有高能物理学中的有用应用,特别是对于喷气机 - 在碰撞中产生的颗粒的准直淋浴,例如Cern大型强子撞机的碰撞。我们探讨了基于图形的AutoEncoders,它们在其“粒子云”表示中的喷射器上运行,并且可以在喷气机内的粒子中利用相互依存的依赖性,用于这种任务。另外,我们通过图形神经网络对能量移动器的距离开发可差的近似,这随后可以用作自动化器的重建损耗函数。
translated by 谷歌翻译
We present a detailed study on Variational Autoencoders (VAEs) for anomalous jet tagging at the Large Hadron Collider. By taking in low-level jet constituents' information, and training with background QCD jets in an unsupervised manner, the VAE is able to encode important information for reconstructing jets, while learning an expressive posterior distribution in the latent space. When using the VAE as an anomaly detector, we present different approaches to detect anomalies: directly comparing in the input space or, instead, working in the latent space. In order to facilitate general search approaches such as bump-hunt, mass-decorrelated VAEs based on distance correlation regularization are also studied. We find that the naive mass-decorrelated VAEs fail at maintaining proper detection performance, by assigning higher probabilities to some anomalous samples. To build a performant mass-decorrelated anomalous jet tagger, we propose the Outlier Exposed VAE (OE-VAE), for which some outlier samples are introduced in the training process to guide the learned information. OE-VAEs are employed to achieve two goals at the same time: increasing sensitivity of outlier detection and decorrelating jet mass from the anomaly score. We succeed in reaching excellent results from both aspects. Code implementation of this work can be found at https://github.com/taolicheng/VAE-Jet
translated by 谷歌翻译
In collider-based particle and nuclear physics experiments, data are produced at such extreme rates that only a subset can be recorded for later analysis. Typically, algorithms select individual collision events for preservation and store the complete experimental response. A relatively new alternative strategy is to additionally save a partial record for a larger subset of events, allowing for later specific analysis of a larger fraction of events. We propose a strategy that bridges these paradigms by compressing entire events for generic offline analysis but at a lower fidelity. An optimal-transport-based $\beta$ Variational Autoencoder (VAE) is used to automate the compression and the hyperparameter $\beta$ controls the compression fidelity. We introduce a new approach for multi-objective learning functions by simultaneously learning a VAE appropriate for all values of $\beta$ through parameterization. We present an example use case, a di-muon resonance search at the Large Hadron Collider (LHC), where we show that simulated data compressed by our $\beta$-VAE has enough fidelity to distinguish distinct signal morphologies.
translated by 谷歌翻译
对异常检测方法的需求不断增长,可以以模型 - 不可知的方式扩大对新颗粒的搜索。大多数新方法的建议专注于信号灵敏度。但是,选择异常事件是不够的 - 还必须有一个策略来为所选事件提供上下文。我们提出了无监督检测的第一个完整的策略,其包括信号灵敏度和用于背景估计的数据驱动方法。我们的技术由两个同时培训的autoencoders建造,被迫彼此去相关。该方法可以脱机用于非共振异常检测,也是第一个完整的在线兼容的异常检测策略。我们表明,我们的方法在为ADC2021数据挑战准备的各种信号上实现了出色的性能。
translated by 谷歌翻译
在2015年和2019年之间,地平线的成员2020年资助的创新培训网络名为“Amva4newphysics”,研究了高能量物理问题的先进多变量分析方法和统计学习工具的定制和应用,并开发了完全新的。其中许多方法已成功地用于提高Cern大型Hadron撞机的地图集和CMS实验所执行的数据分析的敏感性;其他几个人,仍然在测试阶段,承诺进一步提高基本物理参数测量的精确度以及新现象的搜索范围。在本文中,在研究和开发的那些中,最相关的新工具以及对其性能的评估。
translated by 谷歌翻译
我们使用神经网络研究几种简化的暗物质(DM)模型及其在LHC的签名。我们专注于通常的单声角加上缺失的横向能量通道,但要训练算法我们在2D直方图中组织数据而不是逐个事件阵列。这导致较大的性能提升,以区分标准模型(SM)和SM以及新物理信号。我们使用KineMatic单速仪功能作为输入数据,允许我们描述具有单个数据示例的模型的系列。我们发现神经网络性能不依赖于模拟的后台事件数量,如果它们作为$ s / \ sqrt {b} $函数呈现,其中$ s $和$ b $是信号和背景的数量每直方图的事件分别。这提供了对方法的灵活性,因为在这种情况下测试特定模型只需要了解新物理单次横截面。此外,我们还在关于真实DM性质的错误假设下讨论网络性能。最后,我们提出了多模型分类器以更普遍的方式搜索和识别新信号,对于下一个LHC运行。
translated by 谷歌翻译
我们介绍了基于深频自动化器的异常检测技术在激光干涉仪中检测重力波信号的问题。在噪声数据上接受训练,这类算法可以使用无监督的策略来检测信号,即,不瞄准特定类型的来源。我们开发了自定义架构,以分析来自两个干涉仪的数据。我们将所获得的性能与其他AutoEncoder架构和卷积分类器进行比较。与更传统的监督技术相比,拟议战略的无监督性质在准确性方面具有成本。另一方面,在预先计算信号模板的集合之外,存在定性增益。经常性AutoEncoder超越基于不同架构的其他AutoEncoder。本文呈现的复发性自动额片的类可以补充用于引力波检测的搜索策略,并延长正在进行的检测活动的范围。
translated by 谷歌翻译
机器学习在加强和加速寻求新基本物理学方面发挥着至关重要的作用。我们审查了新物理学的机器学习方法和应用中,在地面高能量物理实验的背景下,包括大型强子撞机,罕见的事件搜索和中微生实验。虽然机器学习在这些领域拥有悠久的历史,但深入学习革命(2010年代初)就研究的范围和雄心而产生了定性转变。这些现代化的机器学习发展是本综述的重点。
translated by 谷歌翻译
在背景主导的情况下,通过机器学习和信号和背景之间的可观察者之间的高度重叠来调查LHC在LHC的新物理搜索的敏感性。我们使用两种不同的型号,XGBoost和深度神经网络,利用可观察到之间的相关性,并将这种方法与传统的切割方法进行比较。我们认为不同的方法来分析模型的输出,发现模板拟合通常比简单的切割更好地执行。通过福芙氏分解,我们可以额外了解事件运动学与机器学习模型输出之间的关系。我们认为具有亚霉素的超对称场景作为一个具体示例,但方法可以应用于更广泛的超对称模型。
translated by 谷歌翻译
Recent developments in the methods of explainable AI (XAI) methods allow researchers to explore the inner workings of deep neural networks (DNNs), revealing crucial information about input-output relationships and realizing how data connects with machine learning models. In this paper we explore interpretability of DNN models designed to identify jets coming from top quark decay in high energy proton-proton collisions at the Large Hadron Collider (LHC). We review a subset of existing top tagger models and explore different quantitative methods to identify which features play the most important roles in identifying the top jets. We also investigate how and why feature importance varies across different XAI metrics, how feature correlations impact their explainability, and how latent space representations encode information as well as correlate with physically meaningful quantities. Our studies uncover some major pitfalls of existing XAI methods and illustrate how they can be overcome to obtain consistent and meaningful interpretation of these models. We additionally illustrate the activity of hidden layers as Neural Activation Pattern (NAP) diagrams and demonstrate how they can be used to understand how DNNs relay information across the layers and how this understanding can help to make such models significantly simpler by allowing effective model reoptimization and hyperparameter tuning. By incorporating observations from the interpretability studies, we obtain state-of-the-art top tagging performance from augmented implementation of existing network
translated by 谷歌翻译
我们如何检测异常:也就是说,与给定的一组高维数据(例如图像或传感器数据)显着不同的样品?这是众多应用程序的实际问题,也与使学习算法对意外输入更强大的目标有关。自动编码器是一种流行的方法,部分原因是它们的简单性和降低维度的能力。但是,异常评分函数并不适应正常样品范围内重建误差的自然变化,这阻碍了它们检测实际异常的能力。在本文中,我们从经验上证明了局部适应性对具有真实数据的实验中异常评分的重要性。然后,我们提出了新颖的自适应重建基于错误的评分方法,该方法根据潜在空间的重建误差的局部行为来适应其评分。我们表明,这改善了各种基准数据集中相关基线的异常检测性能。
translated by 谷歌翻译
The abundance of dark matter (DM) subhalos orbiting a host galaxy is a generic prediction of the cosmological framework, and is a promising way to constrain the nature of DM. In this paper, we investigate the use of machine learning-based tools to quantify the magnitude of phase-space perturbations caused by the passage of DM subhalos. A simple binary classifier and an anomaly detection model are proposed to estimate if stars or star particles close to DM subhalos are statistically detectable in simulations. The simulated datasets are three Milky Way-like galaxies and nine synthetic Gaia DR2 surveys derived from these. Firstly, we find that the anomaly detection algorithm, trained on a simulated galaxy with full 6D kinematic observables and applied on another galaxy, is nontrivially sensitive to the DM subhalo population. On the other hand, the classification-based approach is not sufficiently sensitive due to the extremely low statistics of signal stars for supervised training. Finally, the sensitivity of both algorithms in the Gaia-like surveys is negligible. The enormous size of the Gaia dataset motivates the further development of scalable and accurate data analysis methods that could be used to select potential regions of interest for DM searches to ultimately constrain the Milky Way's subhalo mass function, as well as simulations where to study the sensitivity of such methods under different signal hypotheses.
translated by 谷歌翻译
在本文中,我们提出了一种将标准结构嵌入物理数据歧管的方法,该方法具有更简单的指标,例如欧几里得和双曲线空间。然后,我们证明这可能是许多应用程序数据分析管道中的有力一步。在大型强子对撞机上使用逐渐更现实的模拟碰撞,我们表明这种嵌入方法了解了潜在的潜在结构。在欧几里得空间中的体积概念中,我们首次提供了一种可行的解决方案,可以量化对撞机物理学中模型不可知的搜索算法的真实搜索能力(即异常检测)。最后,我们讨论了如何采用本文中提出的思想来解决许多实践挑战,这些挑战需要从复杂的高维数据集中提取物理有意义的表示形式。
translated by 谷歌翻译
当应用于具有高级别方差的目标类别的复杂数据集时,基于异常检测的基于异常检测的方法趋于下降。类似于转移学习中使用的自学学习的想法,许多域具有类似的未标记数据集,可以作为分发超出样本的代理。在本文中,我们介绍了来自类似域的未标记数据的潜在不敏感的AutoEncoder(LIS-AE)用作阳性示例以形成常规AutoEncoder的潜在层(瓶颈),使得它仅能够重建一个任务。我们为拟议的培训流程和损失职能提供了理论理的理由以及广泛的消融研究,突出了我们模型的重要方面。我们在多个异常检测设置中测试我们的模型,呈现定量和定性分析,展示了我们对异常检测任务模型的显着性能改进。
translated by 谷歌翻译
通过使用机器学习技术的异常检测已成为一种新型强大的工具,可以在标准模型之外寻找新物理学。从历史上看,与JET可观察物的发展相似,理论一致性并不总是在算法和神经网络体系结构的快速发展中扮演核心角色。在这项工作中,我们通过使用能量加权消息传递来构建基于图神经网络的红外和共线安全自动编码器。我们证明,尽管这种方法具有理论上有利的特性,但它也对非QCD结构表现出强大的敏感性。
translated by 谷歌翻译
A new Lossy Causal Temporal Convolutional Neural Network Autoencoder for anomaly detection is proposed in this work. Our framework uses a rate-distortion loss and an entropy bottleneck to learn a compressed latent representation for the task. The main idea of using a rate-distortion loss is to introduce representation flexibility that ignores or becomes robust to unlikely events with distinctive patterns, such as anomalies. These anomalies manifest as unique distortion features that can be accurately detected in testing conditions. This new architecture allows us to train a fully unsupervised model that has high accuracy in detecting anomalies from a distortion score despite being trained with some portion of unlabelled anomalous data. This setting is in stark contrast to many of the state-of-the-art unsupervised methodologies that require the model to be only trained on "normal data". We argue that this partially violates the concept of unsupervised training for anomaly detection as the model uses an informed decision that selects what is normal from abnormal for training. Additionally, there is evidence to suggest it also effects the models ability at generalisation. We demonstrate that models that succeed in the paradigm where they are only trained on normal data fail to be robust when anomalous data is injected into the training. In contrast, our compression-based approach converges to a robust representation that tolerates some anomalous distortion. The robust representation achieved by a model using a rate-distortion loss can be used in a more realistic unsupervised anomaly detection scheme.
translated by 谷歌翻译
我们提出了一种用于测试使用吸收材料记录辐射电磁(EM)场的天线阵列的新方法,并使用条件编码器解码器模型通过AI评估所得到的热图像串。鉴于馈送到每个阵列元件的信号的功率和相位,我们能够通过我们训练的模型重建正常序列,并将其与热相机观察到的真实序列进行比较。这些热图仅包含低级模式,例如各种形状的斑点。然后,基于轮廓的异常检测器可以将重建误差矩阵映射到异常的分数,以识别故障的天线阵列,并将分类F量度(F-M)增加到46%。我们在天线测试系统收集的时间序列热量量表上展示了我们的方法。传统上,变形自身摩擦(VAE)学习观察噪声可以产生比具有恒定噪声假设的VAE更好的结果。然而,我们证明这不是对这种低级模式的异常检测的情况,有两个原因。首先,结合所学到的观察噪声的基线度量重建概率不能分化异常模式。其次,具有较低观察噪声假设的VAE的接收器操作特性(ROC)曲线下的区域比具有学习噪声的VAE高出11.83%。
translated by 谷歌翻译