Systems In High Energy Physics Research Articles

Meson content of entanglement spectra after integrable and nonintegrable quantum quenches

We use tensor network simulations to calculate the time evolution of the lower part of the entanglement spectrum and return rate functions after global quantum quenches in the Ising model. We consider ground state quenches towards mesonic parameter ranges with confined fermion pairs as nonperturbative bound states in a semiclassical regime and the relativistic E$_8$ theory. We find that in both cases only the dominant eigenvalue of the modular Hamiltonian fully encodes the meson content of the quantum many-body system or quantum field theory, giving rise to nearly identical entanglement oscillations in the entanglement entropy. When the initial state is prepared in the paramagnetic phase, the return rate density exhibits regular cusps at unequally spaced positions, signaling the appearance of dynamical quantum phase transitions, at which the entanglement spectrum remains gapped. Our analyses provide a deeper understanding on the role of quantum information quantities for the dynamics of emergent phenomena reminiscent of systems in high-energy physics.

Radiation-tolerant all-digital clock generators for HEP applications

The emergence of high-precision timing systems in High Energy Physics motivates new developments in the domain of clock generation and distribution. Particularly, when considering the challenges arising from adopting advanced deep-submicron CMOS technology nodes, all-digital PLL and clock and data recovery (CDR) architectures constitute a promising option for future high energy physics (HEP) experiments. Both LC oscillator and ring oscillator-based all-digital PLL/CDR blocks for front-end ASICs were studied, designed, manufactured and characterized. Their design, the hardening considerations, as well as the performance obtained with these circuits are presented in this article.

Towards quantum simulations in particle physics and beyond on noisy intermediate-scale quantum devices.

We review two algorithmic advances that bring us closer to reliable quantum simulations of model systems in high-energy physics and beyond on noisy intermediate-scale quantum (NISQ) devices. The first method is the dimensional expressivity analysis of quantum circuits, which allows for constructing minimal but maximally expressive quantum circuits. The second method is an efficient mitigation of readout errors on quantum devices. Both methods can lead to significant improvements in quantum simulations, e.g. when variational quantum eigensolvers are used. This article is part of the theme issue 'Quantum technologies in particle physics'.

Toward real-time data query systems in HEP

Exploratory data analysis tools must respond quickly to a user’s questions, so that the answer to one question (e.g. a visualized histogram or fit) can influence the next. In some SQL-based query systems used in industry, even very large (petabyte) datasets can be summarized on a human timescale (seconds), employing techniques such as columnar data representation, caching, indexing, and code generation/JIT-compilation. This article describes progress toward realizing such a system for High Energy Physics (HEP), focusing on the intermediate problems of optimizing data access and calculations for “query sized” payloads, such as a single histogram or group of histograms, rather than large reconstruction or data-skimming jobs. These techniques include direct extraction of ROOT TBranches into Numpy arrays and compilation of Python analysis functions (rather than SQL) to be executed very quickly. We will also discuss the problem of caching and actively delivering jobs to worker nodes that have the necessary input data preloaded in cache. All of these pieces of the larger solution are available as standalone GitHub repositories, and could be used in current analyses.

Radiation Damage in Silicon Photonic Mach–Zehnder Modulators and Photodiodes

Radiation-hard optical links are the backbone of read-out systems in high-energy physics (HEP) experiments at CERN. The optical components must withstand large doses of radiation and strong magnetic fields and provide high data rates. Radiation hardness is one of the requirements that become more demanding with every new generation of HEP experiment. Previous studies have shown that vertical cavity surface emitting lasers, on which the current optical links are based, will not be able to withstand the expected radiation levels in the innermost regions of future HEP experiments. Silicon photonics (SiPh) is currently being investigated as a promising alternative technology to address this challenge. We irradiated SiPh Mach-Zehnder modulators (MZMs) with different design parameters to evaluate their resistance against ionizing radiation. We confirm that SiPh MZMs with a conventional design do not show a phase shift degradation when exposed to a 20-MeV neutron fluence of $3\cdot 10^{16}~{\rm n/cm^{2}}$ . We further demonstrate that custom-designed MZMs with shallow etch optical waveguides and high doping concentrations in their p-n junctions exhibit a strongly improved radiation hardness over devices with a conventional design when irradiated with X-rays. We also found that MZMs withstood higher radiation levels when they were irradiated at a low temperature. In contrast, larger reverse biases during irradiation led to a faster device degradation. Simulations indicate that a pinch-off of holes is responsible for the device degradation. Photodiodes (PDs) were also tested for their radiation hardness as they are needed in silicon photonic transceivers. X-ray irradiation of building-block germanium-silicon PDs showed that they were not significantly affected.

Human Machine Interface for Data Acquisition Systems Applied in High Energy Physics

Nowadays high energy physics scientists build and design systems that are complex in terms of the huge amount of subsystems and individual components. A single subsystem may consist of a few tens of thousands digital and analogue channels and sensors. As a result, the data rates captured in modern systems may result in gigabytes per second. Complex systems could generate various alarms and provide other diagnostic information. Consequently, a huge number of variables are needed to control and monitor the system. It could be a real challenge to provide access to all alarms and diagnostic information in systems composed of thousands of channels. In this sense, it is necessary to develop a Human Machine Interfaces (HMI) that will be simple enough to describe a complex system and detailed enough to present all the relevant information to the operators. The purpose of this paper is to describe and propose an HMI scheme able to obtain and present data from High Energy Physics systems. The purpose of this paper is to evaluate HMI for complex systems. The prototype HMI described is based on the demonstration PXIe-based Neutron Flux Monitor (NFM) developed by the Department of Microelectronics and Computer Science. This NFM is going to provide essential information for plasma operation in the ITER plant. The HMI involves a Graphical User Interface and an Alarm Management Scheme, all based on the Experimental Physics and Industrial Control System (EPICS) framework. The Graphical User Interface (GUI) includes the use of several tools provided by the Control System Studio as well as JavaScript, rules and actions to dynamically present data to the operators. In regards to alarm management, a scheme is proposed to efficiently handle alarms by presenting the relevant information and controls to quickly react to alarms.

Diamond particle detectors systems in high energy physics

With the first three years of the LHC running complete, ATLAS and CMS are planning to upgrade their innermost tracking layers with more radiation hard technologies. Chemical Vapor Deposition (CVD) diamond is one such technology. CVD diamond has been used extensively in beam condition monitors as the innermost detectors in the highest radiation areas of BaBar, Belle, CDF and all LHC experiments. The lessons learned in constructing the ATLAS Beam Conditions Monitor (BCM), Diamond Beam Monitor (DBM) and the CMS Pixel Luminosity Telescope (PLT) all of which are based on CVD diamond with the goal of elucidating the issues that should be addressed for future diamond based detector systems. The first beam test results of prototype diamond devices with 3D detector geometry should further enhance the radiation tolerance of this material.

Lattice gauge tensor networks

We present a unified framework to describe lattice gauge theories by means of tensor networks: this framework is efficient as it exploits the high local symmetry content native to these systems by describing only the gauge invariant subspace. Compared to a standard tensor network description, the gauge invariant model allows one to increase real and imaginary time evolution up to a factor that is square of the dimension of the link variable. The gauge invariant tensor network description is based on the quantum link formulation, a compact and intuitive formulation for gauge theories on the lattice, which is alternative to and can be combined with the global symmetric tensor network description. We present some paradigmatic examples that show how this architecture might be used to describe the physics of condensed matter and high-energy physics systems. Finally, we present a cellular automata analysis which estimates the gauge invariant Hilbert space dimension as a function of the number of lattice sites that might guide the search for effective simplified models of complex theories.

The radiation hardness of Pr:LuAG scintillating ceramics

Scintillating ceramics have been considered to be used in upgraded HL-LHC (high luminosity large hadron collider) systems in high energy physics. However, the relationship between defects, annealing process, and radiation hardness still remains to be explored and understood. In this paper, Pr:LuAG ceramics were investigated as the promising scintillators due to the application requirements in HL-LHC, including the effects of ionizing irradiation, air annealing and sintering aids. Si4+ and Mg2+ were found to promote a concentration increase of oxygen vacancies without causing additional radiation induced color centers, while ionizing irradiation bring severe damage preventing light output. The Pr3+/Pr4+ ions act not only as luminescent center, but also as compensator of intrinsic defects which could be attributed to the distinguish irradiation differences observed between Pr:LuAG and LuAG. Annealing was found to have an opposite effect on radiation induced absorption. From this study, it is confirmed that elimination of specific impurities from raw materials is a demanding step in ceramic optimization, and proper use of sintering aids could not only contribute to the ceramic transparency but also bring less harm to radiation hardness.

Revealing Bell’s nonlocality for unstable systems in high energy physics

Entanglement and its consequences - in particular the violation of Bell inequalities, which defies our concepts of realism and locality - have been proven to play key roles in Nature by many experiments for various quantum systems. Entanglement can also be found in systems not consisting of ordinary matter and light, i.e. in massive meson--antimeson systems. Bell inequalities have been discussed for these systems, but up to date no direct experimental test to conclusively exclude local realism was found. This mainly stems from the fact that one only has access to a restricted class of observables and that these systems are also decaying. In this Letter we put forward a Bell inequality for unstable systems which can be tested at accelerator facilities with current technology. Herewith, the long awaited proof that such systems at different energy scales can reveal the sophisticated "dynamical" nonlocal feature of Nature in a direct experiment gets feasible. Moreover, the role of entanglement and CP violation, an asymmetry between matter and antimatter, is explored, a special feature offered only by these meson-antimeson systems.

Heisenberg’s Uncertainty Relation and Bell Inequalities in High Energy Physics

An effective formalism is developed to handle decaying two-state systems. Herewith, observables of such systems can be described by a single operator in the Heisenberg picture. This allows for using the usual framework in quantum information theory and, hence, to enlighten the quantum feature of such systems compared to non-decaying systems. We apply it to systems in high energy physics, i.e. to oscillating meson-antimeson systems. In particular, we discuss the entropic Heisenberg uncertainty relation for observables measured at different times at accelerator facilities including the effect of CP violation, i.e. the imbalance of matter and antimatter. An operator-form of Bell inequalities for systems in high energy physics is presented, i.e. a Bell-witness operator, which allows for simple analysis of unstable systems.

Developing end‐user tailorable Web applications using a compositional framework

AbstractSince Web‐based applications are typically required to accommodate a rapid development cycle and be adaptable to the needs of heterogeneous communities of users, the ability to continue evolving after deployment (tailoring) is regarded as a valuable property for any software accessible via a WWW‐browser interface. This article introduces a reusable compositional framework to support the development of end‐user‐tailorable applications for the Web. This framework defines the composition of tailorable applications with an object‐scripting technique, based on nested compositional markup specifications. Application tailorability is achieved through the use of a ‘visualizer’ pattern that allows decoupling of tailoring interfaces from primitive components and recomposing fragments of an application at runtime. The framework permits the application of multiple tailoring interfaces (visualizers) to an application instance, reusing tailoring interfaces across multiple application domains and allows for the evolution of visual techniques for carrying out tailoring throughout a project lifecycle. This article summarizes the experience accumulated while developing the proposed framework using the Java 2 platform and introduces two case studies that have been made on the development of remote monitoring applications in the domain of large‐scale control systems in high‐energy physics and interactive multimedia courseware for the Web. Copyright © 2003 John Wiley & Sons, Ltd.

Design patterns for description-driven systems in High Energy Physics

In data modeling, product information has most often been handled separately from process information. The integration of product and process models in a unified data model could provide the means by which information could be shared between High Energy Physics (HEP) groups throughout the system lifecycle from design through to production. Recently attempts have been made to integrate these two separate views of systems through identifying common data models. This paper relates description-driven systems to multi-layer architectures through the CRISTAL project and reveals where existing design patterns facilitate the integration of product and process models, where patterns are missing or require enrichment for integration. It reports on the construction of a so-called description-driven system which integrates Product Data Management (PDM) and Workflow Management (WfM) models through a common meta-model.

Superconducting focusing systems in high energy physics

Optimised focusing systems using superconducting and conventional quadrupoles are compared, with particular reference to particle beams in the momentum range 1 to 1000 GeV/ c. It is shown that, provided certain limitations in superconductor technology can be overcome, high field superconducting lenses could make possible order-of-magnitude reductions in the cost of focusing high energy beams and at the same time allow substantially shorter object-to-image distances than those which are practicable with conventional quadrupoles. A detailed analysis of focusing systems using superconducting solenoids, suggests that in general the latter should become competitive with quadrupoles for beam divergences of 0.1 rad or greater. Beam transport systems are considered separately and it is shown that in a freely designed system conventional quadrupoles should maintain their superiority at all energies; however, any restrictions on length, periodicity or maximum aperture, will increasingly favour the use of superconducting quadrupoles for transport of particles at the higher energies. Transport systems using solenoids or beam guides do not appear to be generally competitive, but may have special applications to low momentum, large divergence beams, if the latter cannot conveniently be matched into a quadrupole system.

Superconducting focusing systems in high energy physics

Optimised focusing systems using superconducting and conventional quadrupoles are compared, with particular reference to particle beams in the momentum range 1 to 1000 GeV/ c. It is shown that, provided certain limitations in superconductor technology can be overcome, high field superconducting lenses could make possible order-of-magnitude reductions in the cost of focusing high energy beams and at the same time allow substantially shorter object-to-image distances than those which are practicable with conventional quadrupoles. A detailed analysis of focusing systems using superconducting solenoids, suggests that in general the latter should become competitive with quadrupoles for beam divergences of 0.1 rad or greater. Beam transport systems are considered separately and it is shown that in a freely designed system conventional quadrupoles should maintain their superiority at all energies; however, any restrictions on length, periodicity or maximum aperture, will increasingly favour the use of superconducting quadrupoles for transport of particles at the higher energies. Transport systems using solenoids or beam guides do not appear to be generally competitive, but may have special applications to low momentum, large divergence beams, if the latter connot conveniently be matched into a quadrupole system.