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Characterization of Degraded Very-High-Energy Heavy-Ion Beams Using the HEARTS LET Booster
No full textVery-high-energy (VHE) heavy ions are particularly relevant for single-event effects (SEEs) testing due to their unique combination of high linear energy transfer (LET) and substantial penetration depth in electronic components, removing the need for vacuum testing and component delidding. The High-Energy Accelerators for Radiation Testing and Shielding (HEARTS) project addresses the growing demand for these types of beams by leveraging the CERN accelerator complex and its use of heavy ions for physics studies and adapting it to radiation testing of electronics. To this end, a detailed characterization of primary and degraded VHE heavy-ion beams has been performed at CERN, using a combination of silicon diode energy measurements and Monte Carlo simulations, to demonstrate their suitability for SEE testing
JEDI-linear: Fast and Efficient Graph Neural Networks for Jet Tagging on FPGAs
No full textGraph Neural Networks (GNNs), particularly Interaction Networks (INs), have shown exceptional performance for jet tagging at the CERN High-Luminosity Large Hadron Collider (HL-LHC). However, their computational complexity and irregular memory access patterns pose significant challenges for deployment on FPGAs in hardware trigger systems, where strict latency and resource constraints apply. In this work, we propose JEDI-linear, a novel GNN architecture with linear computational complexity that eliminates explicit pairwise interactions by leveraging shared transformations and global aggregation. To further enhance hardware efficiency, we introduce fine-grained quantization-aware training with per-parameter bitwidth optimization and employ multiplier-free multiply-accumulate operations via distributed arithmetic. Evaluation results show that our FPGA-based JEDI-linear achieves 3.7 to 11.5 times lower latency, up to 150 times lower initiation interval, and up to 6.2 times lower LUT usage compared to state-of-the-art GNN designs while also delivering higher model accuracy and eliminating the need for DSP blocks entirely. This is the first interaction-based GNN to achieve less than 60~ns latency and currently meets the requirements for use in the HL-LHC CMS Level-1 trigger system. This work advances the next-generation trigger systems by enabling accurate, scalable, and resource-efficient GNN inference in real-time environments. Our open-sourced templates will further support reproducibility and broader adoption across scientific applications
GW231123: a Possible Primordial Black Hole Origin
No full textGW231123, the heaviest binary black hole merger detected by the LIGO-Virgo-KAGRA collaboration to date, lies in the pair-instability mass gap and exhibits unusually high component spins. In this letter, we show that both merging black holes may have a primordial origin with smaller initial masses. The observed masses and, crucially, the spins of GW231123 are naturally accommodated within the most vanilla primordial black hole framework, once cosmological accretion is taken into account. Interestingly, the parameter space needed to explain the inferred GW231123 rate is at the edge of the exclusion region from Xray and CMB observations, suggesting that this interpretation can be either confirmed or ruled out. The upcoming O5 observing run by the collaboration should detect similar events, testing their mass-spin correlation, while next-generation detectors would be capable of observing high redshift events, as predicted in this scenario
ATLAS Inner Detector Operational Experience at the Large Hadron Collider at CERN
No full textThe tracking and vertexing performance of the ATLAS detector relies critically on the silicon and gaseous tracking subsystems that form the ATLAS Inner Detector. They have been operated successfully with high performance in LHC since Run 1 (2010) up to the current date. Those subsystems have undergone significant upgrades to meet the challenges imposed by the higher pileup and luminosity, that are being delivered by the LHC, well beyond its design. Furthermore, the Inner Detector was exposed to a radiation dose higher than what has ever been experienced in any other detectors in high energy physics experiments. Effects of radiation damage on silicon sensors and front-end ASICs were intensively studied. The key status and performance metrics of the Pixel Detector, the Semi Conductor Tracker, and the Transition Radiation Tracker are summarised, and the operational experience and requirements to ensure optimum data quality and data taking efficiency are described
Advancing gravitational wave predictions from cosmological first-order phase transitions
No full textIn this talk, I will discuss how to formulate precise predictions for the parameters of supercooled cosmological first-order phase transitions. I will explain the construction of the high-temperature effective field theory (EFT) applicable to the issue of nucleation. Using this EFT, I will show how to consistently formulate predictions at next-to-leading order in perturbation theory, paying special attention to the issue of various mass/energy scales and how they vary across the bubble
A Tale of Two Uplifts: Parisi-Sourlas with Defects
No full textDefects in conformal field theories (CFTs) play a key role in critical phenomena by modifying scaling behaviors and generating new universality classes. We introduce Parisi-Sourlas (PS) supersymmetry in the presence of extended operators and demonstrate that any -dimensional defect in a CFT can be uplifted to a defect in a PS-supersymmetric CFT. Surprisingly, there are actually two distinct uplifted defects--of dimensions and --which reduce to the original one. We show how this reduction works for correlators with insertions both in the bulk and on the defect. As a byproduct, we find new relations between defect conformal blocks in dimensions and . We further show that the reduction of the -dimensional defect implies and extend a "global symmetry reduction" previously considered in the literature. Finally, we provide various examples of these uplifts, including perturbative computations in epsilon expansion of the uplift of the Ising magnetic line defect, as well as exact computations of observables in the four-dimensional uplift of minimal models with boundaries
Searching non-standard interactions with atmospheric neutrinos at ESSnuSB
No full textAtmospheric neutrinos provide a unique avenue to study neutrino interactions in matter. In this work, the prospects of constraining non-standard neutrino interactions with atmospheric neutrino oscillations are investigated for the proposed ESSnuSB far detector. By analyzing atmospheric neutrino samples equivalent to 5.4 Mtyear exposure, it is found that ESSnuSB could be able to set the upper bounds and at CL, when the results are minimized for and and normal ordering is assumed for neutrino masses. It is also shown that the presence of non-standard interactions could affect the sensitivities to neutrino mass ordering and octant in comparison to the standard interaction scheme. The results of this work highlight the complementarity between atmospheric and accelerator neutrino programs in ESSnuSB
A simple algorithm for polarized parton evolution
No full textWe present an algorithm to include the correlation between the production and decay planes of gluons in a parton-shower simulation. The technique is based on identifying the charge currents responsible for the creation and annihilation of the vector field. It is applicable in both the hard-collinear and the soft wide-angle region. As a function of the number of particles, the algorithm scales linear in computing time and memory. We demonstrate agreement with fixed-order perturbative calculations in the relevant kinematical limits, and present a new observable that can be used to probe correlations beyond current-current interactions
Performance Validation of HGCAL Prototype Modules in a Strong Magnetic Field with Particle Beams from the SPS
No full textThe high granularity calorimeter (HGCAL) will be an entirely new sub-detector of the CMS experiment during the High Luminosity phase (HL-LHC). To ensure its modules meet the stringent performance standards, they undergo extensive testing simulating the conditions in which they will operate. The most recent test, involved placing prototype modules inside a powerful solenoid magnet while shooting different particle beams coming from the Super Proton Synchrotron. These tests are crucial for confirming that the modules will maintain their excellent performance - validated by scientists in various labs around the world - also when placed within the magnetic field of the CMS experiment in the future
Delivery of full production of CLIQ units for HL-LHC
No full textCoupling-Loss-Induced-Quench (CLIQ) units will be integrated into the novel quench protection system for the HL-LHC Inner Triplet superconducting magnets. The full production of these units has recently been delivered to CERN and currently undergoing testing. This photo collection also shows some other work being done for the HL-LHC Project machine protection work package (WP7)