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ALPHA Progress and Status Report 2024
No full textProgress report of the ALPHA Collaboration following the 2024 run
ATLAS WLCG Data Challenge 2024 planning and implementation
No full textATLAS is participating in the WLCG Data Challenges, a bi-yearly program established in 2021 to prepare for the data rates of the High Luminosity HL-LHC. In each challenge, the transfer rates are increased to ensure readiness for the full rates by 2029. The goal of the 2024 Data Challenge (DC24) was to reach 25\% of the HL-LHC expected transfer rates, with each experiment deciding how to execute the challenge based on agreed general guidelines and common dates. The ATLAS challenge was designed to test the ATLAS distributed infrastructure across 66 sites and was carried out over 12 days, with increasing rates and more complex transfer topologies, putting significant strain on the system. It was also the first time the new OAuth 2.0 authorization system was tested at such a large scale. This paper will discuss the planning of the challenge, the tools used to execute it, the agreed-upon transfer rates for the connections, and finally, the achieved results and any unrealized goals, along with an analysis of the bottlenecks. We will then describe how the challenge itself was executed, the results obtained, and the lessons learned. Finally, we will look ahead to the next challenge, currently scheduled for end of 2026 or early in 2027, with 50\% of HL-LHC rates
International Conference on Quantum Technologies for High-Energy Physics
No full textIn this work, we study a Quantum Generative Model based on the Quantum Chebyshev Transform that enables to learn and sampling probability distributions. The model is applied to fragmentation functions, which quantify the probability that a given parton decays into a particular hadron after a hard scattering event. The results show that this model enables an efficient sampling, performing a natural quantum interpolation when the sampling is executed on an extended register, a task that might be challenging to perform classically. Furthermore, we investigate the model's performance when correlations between the momentum fraction and the energy scale are introduced via entanglement in quantum circuits. This study provides valuable insights into the correlations of these two variable
International Conference on Quantum Technologies for High-Energy Physics
No full textQuantum computers may revolutionize event generation for collider physics by allowing calculation of scattering amplitudes from full quantum simulation of field theories. Although rapid progress is being made in understanding how best to encode quantum fields onto the states of quantum registers, most formulations are lattice-based and would require an unrealistically large number of qubits when applied to scattering events at colliders with a wide momentum dynamic range. In this regard, particle-based formulations of field theory dynamics developed in works such as Barata et al. (Phys. Rev. A 103) and Gálvez-Viruet (arXiv:2406.03147) are highly attractive for their qubit efficiency and strong association with scattering. In fact, we believe that adopting some sort of sparse Fock representation is the only viable approach to realizing quantum event generators.
Since particle-based formulations are uncommon, basic properties such as their relation to analytic perturbation theory calculations are yet to be established. In this presentation, we compare physical observables computed numerically through a particle-based formulation to corresponding results of perturbation theory calculation using the 1+1d scalar field theory. We then discuss a possible roadmap to realizing quantum event generators, describing the known unknowns along the way
International Conference on Quantum Technologies for High-Energy Physics
No full textQuantum computers are a promising platforms to efficiently simulate systems hard to tackle on classical machines. An important challenge to overcome is the efficient control of errors that, if left undisturbed, make quantum simulations useless. A solution to this challenge is quantum error correction, that exploiting redundancy is able to correct errors. In this talk I will explore the connections between quantum error correction and lattice gauge theories and exploit them to propose a path forward for error corrected simulations of interest for high energy physics
Adoption of ROOT RNTuple for the next main event data storage technology in the ATLAS production framework Athena
No full textSince the start of LHC in 2008, the ATLAS experiment has relied on ROOT to provide storage technology for all its processed event data. Internally, ROOT files are organized around TTree structures that are capable of storing complex C++ objects. The capabilities of TTrees developed over the years and are now offering support for advanced concepts like polymorphism, schema evolution and user defined collections and ATLAS makes use of these features to handle its EDM. But some original TTrees concepts, like the POSIX file model and sequential writing, remain unchanged since the beginning and could be an obstacle to achieving the performance required for High Luminosity LHC. With the HL-LHC performance goals in mind, the ROOT project developed a new storage format - the RNTuple. RNTuple, with its accompanying user API, is now in the final development stage and is planned to be production-ready at the end of 2024. Soon after that, the TTree will become a legacy format. ATLAS intends to have its main Event processing framework Athena ready to use RNTuple in the production environment as early as possible. The work on adopting RNTuple as another ROOT storage technology in Athena started already in 2021 and is now nearly complete. Although the initial goal was to focus on derived-AOD products (PHYS and PHYSLITE), with a little added effort all ATLAS data products: RDO, HITS, ESD, AOD and DAOD can be now stored in RNTuple format and transparently read back. In this paper we will describe the current state of RNTuple adoption in the Athena framework and explain the ATLAS EDM requirements that had to be met on the ROOT side to successfully integrate both environments. We will demonstrate the ability to run standard ATLAS production workflows, based on RNTuple as the Event data storage technology, and point out key advantages of the new format
ATLAS software tools to handle ROOT RNTuple
No full textThe software of the ATLAS experiment at the CERN LHC accelerator contains a number of tools to inspect (validate, summarize, peek into etc.) all its official data formats recorded in ROOT files. These tools --- mainly written in the Python programming language --- handle the ROOT TTree which is currently the main storage object format of ROOT files. However, the ROOT project has developed an alternative to TTree, called RNTuple. The new storage format offers significant improvements and ATLAS plans to adopt it in LHC Run 4. Work is ongoing to enhance the tools in order to handle the RNTuple storage format in addition to TTree in a transparent for the user way. The work is aided by modern and detailed APIs provided by RNTuple. We will present the progress made and lessons learnt
3D integration of pixel readout chips using Through-Silicon-Vias
No full textParticle tracking and imaging detectors are becoming increasingly complex, driven by demands for densely integrated functionality and maximal sensitive area. These challenging requirements can be met using 3D interconnect techniques widely used in industry. In this paper, we present the results of an evaluation of the 3D Through-Silicon-Via (TSV) technology, using the Timepix4 integrated circuit as a test-vehicle. We will present the concepts for 3D integration and test results from TSV-processed chips bonded to custom-designed circuit boards conceived as proofs-of-principle for future detector modules