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Probing scalar and pseudoscalar new physics using rare kaon decays
No full textRare kaon decays provide sensitive tests of new physics. In this work, we focus on scalar and pseudoscalar operators, analysing the and decays. We highlight the complementary role of different modes: , in particular the forward-backward asymmetry in the muon channel as a clean probe of scalar effects, the stringent constraints from , and the discovery potential of future measurements of and . The interplay between charged and neutral modes underscores the complementarity of NA62, the LHCb upgrade, and KOTO-II
Overview of recent results from the ATLAS experiment
No full textThe talk "Overview of recent results from the ATLAS experiment" will be presented at the MIAMI2025 conference (30 min)
Recent searches for new phenomena with the ATLAS detector
No full textMany theories beyond the Standard Model (SM) have been proposed to address several of the SM shortcomings, such as explaining why the Higgs boson is so light, the origin of neutrino masses, or the observed pattern of masses and mixing angles in the quark and lepton sectors. Many of these beyond-the-SM extensions predict new particles or interactions directly accessible at the LHC. This talk will present some highlights on recent searches by the ATLAS detector at the LHC
Measurement of the sensitivity of two-particle correlations in pp collisions to the presence of hard scatterings with the ATLAS detector
No full textA key open question in the study of multi-particle production in high-energy collisions is the relationship between the ``ridge'' - observed azimuthal correlations between particles in the underlying event that extend over all rapidities and hard or semi-hard scattering processes. In particular, it is not known whether jets or their soft fragments are correlated with particles in the underlying event. These proceedings present ATLAS measurements of two-particle correlations in collisions at TeV with two different particle-pair selections. In the first case, charged particles associated with jets are excluded from the correlation analysis. This shows that excluding charged particles associated with jets does not affect the measured correlations. In the second case, correlations are measured between particles within jets and charged particles from the underlying event. Particles associated with jets do not exhibit any significant azimuthal correlations with the underlying event, ruling out hard processes contributing to the ridge
LHCb - Heavy Neutral Lepton Searches at the LHCb Experiment
No full textHeavy Neutral Leptons (HNLs) are hypothetical long-lived particles that extend the Standard Model (SM) and provide a natural explanation for the non-zero neutrino masses. In addition, they could play a key role in addressing some of the most profound open questions in particle physics and cosmology, including the origin of the matter–antimatter asymmetry via baryogenesis. In this poster, we present the status and state-of-the-art of HNL searches at the LHCb experiment. We report the latest and most stringent LHCb limits on muon-coupled HNLs in the 1.6–5 GeV mass range, obtained from a Run 2 (2016–2018) analysis targeting displaced vertices corresponding to HNL flight distances of 0.02–0.5 m. Looking ahead, for Run 3 we introduce a novel reconstruction technique that exploits track segments downstream of the LHCb magnet, thereby extending the accessible displacement window to 0.5–8.0 m. This approach enhances sensitivity dramatically, providing a 40-fold increase in the number of accessible HNL events and extending the lifetime reach by a factor of 16 compared to the Run 2 analysis. A dedicated sensitivity study shows how these improvements translate into a significantly extended reach in the HNL mass–coupling parameter space, positioning LHCb to set world-leading constraints on HNLs
Recent results from ATLAS on exotica
No full textSearch for exotic hadrons, including tetraquark and pentaquark candidates, decaying into J/ψ, ψ(2S), or Υ states, in association with other charged hadrons and muons, using ATLAS Run 1 and Run 2 datasets from proton–proton collisions at center-of-mass energies of 7, 8, and 13 TeV
Radiation-Tolerant Universal Control Electronics for Energy Extraction Systems at CERN
No full textThis paper presents a novel radiation-tolerant Universal Control Electronics (UCE) platform for CERN's Energy Extraction Systems (EESs). Addressing the critical needs of safety, redundancy, and long-term reliability in high-radiation environments, the UCE replaces unique legacy systems with a modular, radiation-tolerant architecture that unifies control across all EES topologies. The system ensures robust operation through extensive redundancy at the component and functional levels, supporting complete fail-safe behaviour that is robust to power loss or faults. Universality is achieved via interchangeable hardware modules, simplifying maintenance and future expansion. With confirmed operational integrity until 512 Gy through CHARM irradiation campaigns, the UCE exceeds the stringent radiation tolerance and performance requirements, which improve with an increase in Total Ionising Dose (TID). A semi-empirically derived radiation effects simulation model was used to estimate the behaviour of a circuit under varying TID accurately and aid in tuning circuit parameters to achieve a sub-5 s baseline system triggering response at 512 Gy. This universal, high-reliability solution is a significant advancement toward a scalable and maintainable EES control infrastructure for the High Luminosity-Large Hadron Collider upgrade
Characterization of an IRRAD beam profile monitor at the CERN T8 beamline and possible improvements via cross-analysis with multiwire proportional chamber
No full textThe IRRAD Proton Facility at CERN relies on locally designed beam-profile monitors (BPM) to supervise the high-intensity 24 GeV/c proton beam extracted, for irradiation experiment purposes, from the CERN Proton Synchrotron. Based on metal-nano-layer sensors and readout electronics leveraging a Charge-Sensitive Amplifier with integrated 20-bit ADC and ARM controller, such a BPM features minimal particle interaction, good radiation hardness, and high sensitivity. Yet, the growing users’ demand for precise irradiation of modern electronics requires ever more detailed beam information, thus driving the introduction of future IRRAD upgrades.
In this paper, we investigate whether improved irradiation precision can be obtained by leveraging the presence of an additional IRRAD-based detector, a MultiWire Proportional Chamber (MWPC). Using beam-profiling data collected both at the BPM and MWPC levels over a period of multiple days, we performed a comparison analysis of data-driven analytical models of both sensors. Given that MWPC provides wider spatial coverage, with a bit lower precision, than BPM but is not as radiation-hard, we suggest that data fusion guided by both models and advanced data-processing software can be used to enhance the apparent characteristics provided by the IRRAD BPM-based beam-profiling system. These results are crucial for the future improvements needed to handle the profile monitoring of new types of beams in IRRAD, e.g., heavy-ion and low-intensity proton beams