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Neural Network Method of Controllers’ Parametric Optimization with Variable Structure and Semi-Permanent Integration Based on the Computation of Second-Order Sensitivity Functions
No full textThis article presents a method for researching processes in automatic control systems based on the operator approach for modelling the control object and the controller. Within the method framework, a system of equations has been developed that describes the relations between the control error, the reference and control action, the output coordinate and the controller and the control object operators. The traditional PI controller modification, including a switching function for adaptation to operating conditions, allows for the system’s effective control in real time. The controller optimization algorithm is based on a functional expression with weighting coefficients that take into account control errors and the control action. To train the neural network through implementing the proposed method, a multilayer architecture was used, including nonlinear activation functions and a dynamic training rate, which ensure high accuracy and accelerated convergence. The TV3-117 turboshaft engine was chosen as the research object, which allows the method to be demonstrated in practical applications in aviation technology. The experimental results showed a significant improvement in control characteristics, including a reduction in the gas-generator rotor speed parameter transient time to ≈1, which is two times faster than the traditional method, where the transient process reaches ≈0.5. The model achieved a maximum accuracy of 0.993 with 160 training epochs, minimizing the error function to 0.005. In comparison with similar approaches, the proposed method demonstrated better results in accuracy and training speed, which was confirmed by a reduction in the number of iterations by 1.36 times and an improvement in the mean square error by 1.86–6.02 times
Searches for additional Higgs bosons (including BSM H125 decays)
No full textThe discovery of the Higgs boson with the mass of about 125 GeV completed the particle content predicted by the Standard Model. Even though this model is well established and consistent with many measurements, it is not capable of explaining some observations by itself. Many extensions of the Standard Model addressing such shortcomings introduce additional Higgs bosons, beyond-the-Standard-Model couplings to the Higgs boson, or new particles decaying into Higgs bosons. In this talk, the latest searches in the Higgs sector are reported, with emphasis on the results obtained with the full LHC Run 2 dataset at 13 TeV. In particular, these include a series of searches for low-mass resonances in merged or boosted topologies, as well as di- and triple-Higgs searches
Investigating the system size dependence of hypernuclei production with A < 5 using the ALICE detector
No full textThe production of (anti)hypernuclei is among the most promising probes for studying the production mechanism of light nuclei in high-energy hadronic collisions. According to coalescence predictions, the production of 3ΛH, 4ΛH, and 4ΛHe is sensitive to their internal wave function. In contrast, the yields predicted with the Statistical Hadronitazion Models (SHM) are based on the mass of the (hyper)nuclei and the freeze-out temperature, with no explicit dependence on the nuclear structure. In these proceedings, the measurements of 3ΛH, 4ΛH, and 4ΛHe from pp to central Pb–Pb collisions are presented. The results are based on the data samples collected by ALICE during the LHC Run 2 and Run 3. For the 3ΛH, in addition, an innovative method to extract its properties based on the system size dependency of its production yield is also presented
Probing initial state effects in nuclear collisions via dijet and spectator neutron measurements with the ATLAS detector
No full textThe measurement of dijets in proton-lead collisions at the LHC provides unique possibilities for investigating both nuclear and nucleon initial state effects as a function of parton scattering kinematics. In particular, color fluctuation effects can significantly alter the average interaction strength of the proton, biasing the number of nucleon-nucleon interactions with the Pb nucleus and, therefore, the event activity. Both event activity and break-up neutrons, detected by Zero Degree Calorimeters, are common estimators used to assess the geometry of the p+Pb collision. This talk presents recent results obtained through the analysis of dijet events in TeV p+Pb data collected by ATLAS in 2016. ATLAS has measured the sensitivity of both forward transverse energy and zero-degree spectator neutron energy to changes in the Bjorken- of the parton extracted from the proton () in the hard-scattering. Both these estimators exhibit a systematic negative bias in events characterized by a high- , although the spectator neutron energy is found to be much less sensitive to these selections than the forward transverse energy. By measuring geometry estimators in well-separated regions of rapidity, this result can provide complementary constraints for color fluctuation modeling. Furthermore, the spectator neutron energy is a novel observable that is influenced by the number of wounded nucleons and the dynamics of nuclear evaporation
NomAD: Real-Time Unsupervised Anomaly Detection at the ATLAS Level-1 Trigger
No full textWe present NomAD (Nanosecond Anomaly Detection), an unsupervised machine learning algorithm developed for real-time anomaly detection in the ATLAS Level-1 Topological (L1Topo) trigger during Run 3. Combining a Variational Autoencoder with Decision Tree Regression, NomAD identifies rare and unconventional events in FPGA-based trigger hardware with low latency. Applied to dimuon events, the algorithm captures signals beyond standard selections, achieving up to a 21% increase in unique acceptance using B-Physics benchmarks. The anomaly detection trigger operates at a tunable rate, with around 1.8 kHz observed at a representative AD score threshold. This flexibility enables integration into existing trigger menus while maintaining sensitivity to new physics. This talk will cover the algorithm's design, performance, and its potential to enhance real-time event selection in high-energy physics
LHC as a Photon Collider for Probing the Standard Model in Heavy Ion Collisions with ATLAS
No full textIn ultra-relativistic heavy-ion collisions, copious rates of processes are expected through the interaction of the large electromagnetic fields of the heavy nuclei. These can lead to photon-induced production of particles such as lepton pairs. In ultra-peripheral collisions (UPCs), characterized by large impact parameters between the nuclei, a di-photon interaction can be the only one taking place, leading to very clean signatures in the detector. The outgoing leptons are back-to-back in the transverse plane, which allows a precise and efficient identification. This poster presents the most recent UPC-based measurement of production, performed using data from the ATLAS experiment recorded in Pb+Pb collisions. The measurement is used to extract properties of the -lepton and probe for new physics contributions. Measured cross-sections will be presented, and the implications for these results on physics processes beyond the Standard Model will be discussed
Jet substructure measurements with large radius jets with ATLAS
No full textJet substructure measurements in heavy-ion collisions offer vital insights into the dynamics of jet quenching within the hot and dense QCD medium generated in these events. In this talk, we present new results from the ATLAS Collaboration on jet suppression and substructure using the Soft-Drop grooming technique in Pb+Pb and $pp$ collisions at . The study explores jet splitting across a broad range of angles for large-radius jets (), using charged particles to achieve high precision, providing access to small angular separations. This work unifies two previously published ATLAS analyses on small- and large- jets, providing a more comprehensive view of jet substructure. The degree of jet suppression is characterized by the nuclear modification factor , presented as a function of jet transverse momentum , the opening angle of the hardest internal splitting , and the transverse momentum scale . By comparing these results with theoretical models, we deepen our understanding of jet quenching mechanisms, explore the properties of the QCD medium, and challenge current theoretical frameworks in heavy-ion collisions
Top Quark at the New Physics Frontier
No full textThis Special Issue on "Top Quark at the New Physics Frontier" is devoted to the most massive fundamental elementary particle known, the top quark. The aim is to provide a comprehensive review of the current status and prospects of top quark physics at the Large Hadron Collider (LHC) and future colliders. We included articles that emphasize where the present understanding is incomplete and suggest new directions for research in this area
Measurement and Monte Carlo simulation of steel and copper activation at the CHARM and CSBF facilities at CERN
No full textPrediction of residual radiation levels in particle accelerator facilities is crucial to ensure their safe and continuous operation over long periods of time. At the European Organization for Nuclear Research (CERN), radiological characterization studies of activated components in experimental areas and various machines within the accelerator complex are performed with Monte Carlo radiation transport codes. To ensure the accuracy of the calculations, a comparison with the experimental data is crucial. This work investigates the induced radioactivity in selected materials commonly used in particle accelerator elements and high-energy physics detector components. Conducted at the CERN High-energy AcceleRator Mixed-field (CHARM) facility, the activation experiments focused in particular on copper and two steel alloys and the medium- to long-lived radionuclides (54Mn, 57Co, 58Co, and 60Co) produced within them. FLUKA Monte Carlo simulations were performed and the comparison with the experimental data showed a satisfactory agreement. •Study of activation in materials used in high-energy particle accelerators.•Experiments conducted at the CHARM and CSBF facilities at CERN.•FLUKA Monte Carlo simulations performed to predict the radionuclide inventories.•Experimental results validate simulations for radiation protection in accelerators