A low-latency graph computer to identify metastable particles at the Large Hadron Collider for real-time analysis of potential dark matter signatures

Image recognition is a pervasive task in many information-processing environments. We present a solution to a difficult pattern recognition problem that lies at the heart of experimental particle physics. Future experiments with very high-intensity beams will produce a spray of thousands of particles in each beam-target or beam-beam collision. Recognizing the trajectories of these particles as they traverse layers of electronic sensors is a massive image recognition task that has never been accomplished in real time. We present a real-time processing solution that is implemented in a commercial field-programmable gate array using high-level synthesis. It is an unsupervised learning algorithm that uses techniques of graph computing. A prime application is the low-latency analysis of dark-matter signatures involving metastable charged particles that manifest as disappearing tracks.

The profile of the Higgs boson: status and prospects

The Higgs boson, which was discovered at CERN in 2012, stands out as a remarkable elementary particle with distinct characteristics. Unlike any other observed particle, it possesses zero spin within the Standard Model (SM) of particle physics. Theoretical predictions had anticipated the existence of this scalar boson, postulating its interaction with the [Formula: see text] and [Formula: see text] bosons as well as through Yukawa interactions with fermions. Furthermore, the Higgs boson can interact with itself, commonly referred to as the Higgs self-interaction. In this review, the current state of experimental and theoretical investigations of Higgs boson production at the Large Hadron Collider and the ongoing efforts to unravel its properties are described, and an up-to-date assessment of our understanding of the Higgs sector of the SM is provided. In addition, potential links between the Higgs boson and significant unresolved questions within the realm of particle physics are presented. This article is part of the theme issue 'The particle-gravity frontier'.

Low energy SUSY confronted with new measurements of W-boson mass and muon g-2

The new CDF II measurement of W-boson mass shows a 7σ deviation from the standard model (SM) prediction, while the recent FNAL measurement of the muon g-2 shows a 4.2σ deviation (combined with the BNL result) from the SM. Both of them strongly indicate new physics beyond the SM. In this work, we study the implication of both measurements on low energy supersymmetry. With an extensive exploration of the parameter space of the minimal supersymmetric standard model (MSSM), we find that in the parameter space allowed by current experimental constraints from colliders and dark matter detections, the MSSM can simultaneously explain both measurements on the edge of 2σ level, taking theoretical uncertainties into consideration. The favored parameter space, characterized by a compressed spectrum between bino, wino and stau, with the stop being around 1 TeV, may be covered in the near future LHC searches.

Organizational complexity in big science: strategies and practices

Studies on 'Big Science' have shifted our perspective from the complexity of scientific objects and their representations to the complexity of sociotechnical arrangements. However, how scientists in large-scale research attend to this complexity to facilitate and afford knowledge production has rarely been considered to date. In this article, we locate organizational complexity on the level of organizing practices that follow multiple and divergent logics. We identify three strategies of managing organizational complexity, drawing on existing literature on large-scale research as well as own empirical research. The three strategies are: segmenting research infrastructure, introducing elements of bureaucratic governance, and implementing standards and standardization. We illustrate these strategies with examples from our empirical case study on experimental particle physics research at CERN's Large Hadron Collider. While the strategies we identified help to cope with the complexity of some organizational tasks by dividing, ordering, or mediating between divergent organizational logics, we find that organizational complexity overall is not reduced but rather displaced. We argue that dealing with complexity is a dynamic and ongoing process, which inevitably generates novel organizational complexity.

Searching for long-lived particles at the Large Hadron Collider and beyond

We discuss the hunt for long-lived particles at the Large Hadron Collider. A motivation is given for such searches, and the experimental challenges are presented. It has become clear in the last few years that the present experiments are not optimally equipped to cover the full phase space of possibilities for such scenarios, so recently small additional experiments have been proposed for specific searches. This article is part of a discussion meeting issue 'Topological avatars of new physics'.

Supersymmetric dark matter in the harsh light of the Large Hadron Collider

I review the status of the model of dark matter as the neutralino of supersymmetry in the light of constraints on supersymmetry given by the 7- to 8-TeV data from the Large Hadron Collider (LHC).