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Towards direct nonlinear compression of long-pulse lasers to the femtosecond regime
No full textA concept to efficiently transfer energetic near-nanosecond pulses to the sub-picosecond scale is proposed: Pre-shaped pulses are sent into multi-mirror multi-pass cells which enable km-scale nonlinear propagation. In this way, the initial pulse bandwidth can be extended by more than three orders of magnitude. To verify the concept, spectral broadening of 100-mJ, 300-ps pulses to a sub-300 fs transform-limit in a 1-m diameter multi-pass cell was simulated. Moreover, an 11-mirror cell was set-up and 300 MW peak power pulses were spectrally broadened in air over 297 passes. The experiments showed that excellent beam quality and high-power transmission can be obtained in the investigated multi-mirror arrangements. The concept presents a new gateway for industrial mature, high-power lasers to the ultrafast regime and is, for instance, attractive for high repetition rate laser-particle acceleration applications
Transient Simulations of MAPS using TCAD, Allpix Squared & SPICE
No full textMonolithic Active Pixel Sensors (MAPS) designed in a 65 nm CMOS imaging technology are an alternative to hybrid pixel sensors as they eliminate the demand for flip-chip bonding while reducing material budget through thinner active sensor layers. The TANGERINE project aims to create a 65 nm MAPS sensor with a small collection electrode for use in future lepton colliders and beam telescopes. This project encompasses the entire sensor R&D process, including electronics and design, simulations, prototype characterization, laboratory testing, and test beam measurements.Predicting the behavior of these sensors is challenging due to the intricate interaction between the doping regions in the small collection electrode design, which results in nonlinear electric fields. As a result, detailed simulations are critical for estimating sensor performance and directing design adjustments. The simulation strategy combines Monte Carlo simulations with electric field fields from Technology Computer-Aided Design (TCAD).Based on this approach, more detailed studies can be performed. This paper focuses on transient simulations to analyze sensor response over time, providing helpful information into charge collection dynamics and timing performance
CaloHadronic : a diffusion model for the generation of hadronic showers
No full textSimulating showers of particles in highly-granular calorimeters is a key frontier in the application of machine learning to particle physics. Achieving high accuracy and speed with generative machine learning models can enable them to augment traditional simulations and alleviate a major computing constraint. Recent developments have shown how diffusion based generative shower simulation approaches that do not rely on a fixed structure, but instead generate geometry-independent point clouds, are very efficient. We present a transformer-based extension to previous architectures which were developed for simulating electromagnetic showers in the highly granular electromagnetic calorimeter of the International Large Detector, ILD. The attention mechanism now allows us to generate complex hadronic showers with more pronounced substructure across both the electromagnetic and hadronic calorimeters. This is the first time that machine learning methods are used to holistically generate showers across the electromagnetic and hadronic calorimeter in highly granular imaging calorimeter systems. The code is available at https://github.com/FLC-QU-hep/CaloHadronic
Methodology for the integration of the array control and data acquisition system with array elements of the Cherenkov Telescope Array Observatory
No full textThe Cherenkov Telescope Array Observatory (CTAO) is the next-generation atmospheric Cherenkov gammaray Observatory. CTAO will be constructed on two sites, one array in the Northern and the other in the Southern hemisphere, containing telescopes of three different sizes, for covering different energy domains. To combine and orchestrate the different telescopes and auxiliary instruments (array elements), the Array Control and Data Acquisition (ACADA) system is the central element for the Observatory on-site operations: it controls, supervises, and handles the data generated by the array elements. Considering the criticality of the ACADA system for future Observatory operations, corresponding quality assurance provisions have been made at the different steps of the software development lifecycle, with focus on continuous integration and testing at all levels. To enable higher-level tests of the software deployed on a distributed system, an ACADA test cluster has been set up to facilitate testing and debugging of issues in a more realistic environment. Furthermore, a separate software integration and test cluster has also been established that allows for the off-site testing of the integrated software packages of ACADA and of the corresponding array elements. Here the software integration can be prepared, interfaces and interactions can be tested, and on-site procedures that are required later in the process can be checked beforehand, only limited by the simulation capabilities that are delivered as part of the software packages. Once preparations and testing with the off-site test cluster are completed, the integrated software can be deployed at the target site. The software packages and setup parameters are kept under configuration control at all stages, and deployment steps are documented to ensure that installations are reproducible. This methodology has been applied for the first time in the context of the integration of ACADA with the first CTAO Large-sized Telescope (LST-1) in October 2023
Quantum Computing 2+1-dimensional Quantum Electrodynamics
No full textThis thesis investigates advances in quantum simulation methods for lattice gauge theories, with a focus on (2+1)-dimensional quantum electrodynamics (QED), which shares important features with (3+1)-dimensional quantum chromodynamics (QCD), such as confinement and asymptotic freedom. Two main projects are developed. The first project investigates the ongoing coupling in a compact pure U(1) gauge theory using a step-scaling function approach. A quantum variational method allows calculations over a wide range of couplings. Plaquette expectation value results are compared with classical Monte Carlo simulations to obtain, in principle, the physical value of the lattice spacing. This method can potentially be extended to the study of QED, which also includes fermionic matter. The second project investigates the static potential between two charges, analyzing the Coulomb, confining, and string-breaking regimes. It involves the development of a tailored variational approach that incorporates system symmetries and mutual information to represent fermionic degrees of freedom. Results from a trapped-ion quantum device agree well with classical simulations, validating the method. Furthermore, this work evaluates superconducting quantum devices, noting issues with noise but also demonstrating improvements in hardware and potential through error limitation. Overall, this work underscores the feasibility of variational quantum algorithms for lattice gauge theory simulations and demonstrates their promise for advancing theoretical physics with quantum computers. This thesis explores advancements in quantum simulation methods for lattice gauge theories, focusing on (2+1)-dimensional Quantum Electrodynamics (QED), which shares key features with (3+1)-dimensional Quantum Chromodynamics (QCD), such as confinement and asymptotic freedom. Two main projects are developed. The first investigates the running coupling in a compact U(1) pure gauge theory using a step scaling function approach. A quantum variational method enables computation across a wide range of couplings. The plaquette expectation value is matched with classical Monte Carlo simulations to obtain, in principle, the physical value of the lattice spacing. This method can be eventually extended to study QED, where fermionic matter is included. The second project examines the static potential between two charges, analyzing Coulomb, confining, and string-breaking regimes. It involves developing a custom variational Ansatz that incorporates system symmetries and mutual information to represent fermionic degrees of freedom. Results from a trapped-ion quantum device align well with exact classical simulations, validating the method. Additionally, the thesis evaluates superconducting devices, identifying noise challenges but noting improvements in hardware and the potential of error mitigation. Overall, this work highlights the viability of variational quantum algorithms for lattice gauge theory simulations and demonstrates their promise for advancing theoretical physics with quantum computing
Measurement of the boson decay branching fraction ratio in proton-proton collisions at = 13 TeV
No full textThe most precise measurement to date of the W boson hadronic decay branching fraction ratio = (W cq)/(W ) is presented. The measurement is based on a sample of proton-proton collision data from the CERN LHC collected by the CMS experiment at a center-of-mass energy of 13 TeV in 2016-2018 with an integrated luminosity of 138 fb. The large cross section of top quark-antiquark production at the LHC offers a sizable high-purity sample of \PW bosons suitable for this measurement. Events with one charged lepton (electron or muon) and at least four jets, two tagged as bottom quark jets, are analyzed. Charm jets are tagged using the presence of a muon inside the jet. The result, = 0.489 0.020, is consistent with the standard model prediction and is twice as precise as the current world-average value
Hidden symmetries of 4D = 2 gauge theories
No full textWe study the global symmetries of the ℤ-orbifold of = 4 Super-Yang-Mills theory and its marginal deformations. The process of orbifolding to obtain an = 2 theory would appear to break the SU(4) R-symmetry down to SU(2) × SU(2) × U(1). We show that the broken generators can be recovered by moving beyond the Lie algebraic setting to that of a Lie algebroid. This remains true when marginally deforming away from the orbifold point by allowing the couplings of the SU(N) × SU(N) gauge groups to vary independently. The information about the marginal deformation is captured by a Drinfeld-type twist of this SU(4) Lie algebroid. The twist is read off from the F- and D- terms, and thus directly from the Lagrangian. Even though at the orbifold point the algebraic structure is associative, it becomes non-associative after the marginal deformation. We explicitly check that the planar Lagrangian of the theory is invariant under this twisted version of the SU(4) algebroid and we discuss implications of this hidden symmetry for the spectrum of the = 2 theory
Off-shell expansion relation of the Yang-Mills scalar theory
No full textIn this work, we investigated the off-shell expansion relation of the Yang-Mills scalar theory. We explicitly showed that the single-trace Berends-Giele currents in the Yang-Mills scalar theory can be decomposed into a term expressed by a linear combination of bi-adjoint scalar Berends-Giele currents and one that vanishes under the on-shell limit. We proved that the bi-adjoint scalar currents, as well as the corresponding coefficients, can be characterized by a graphic approach that was originally studied in the Einstein-Yang-Mills expansion. Furthermore, we generalized the decomposition to the multitrace case through unifying relations and established the connection both in single-trace and multitrace graphic descriptions. Finally, we established the relations between the Yang-Mills currents and the single-trace Yang-Mills scalar currents, choosing special reference orders of the Yang-Mills graphs