Grinstein, B., Lu, X. C., Miro, C., & Quilez, P. (2025). Accidental symmetries, Hilbert series, and friends. J. High Energy Phys., 03(3), 172–86pp.
Abstract: Accidental symmetries in effective field theories can be established by computing and comparing Hilbert series. This invites us to study them with the tools of invariant theory. Applying this technology, we spotlight three classes of accidental symmetries that hold to all orders for non-derivative interactions. They are broken by derivative interactions and become ordinary finite-order accidental symmetries. To systematically understand the origin and the patterns of accidental symmetries, we introduce a novel mathematical construct – a (non-transitive) binary relation between subgroups that we call friendship. Equipped with this, we derive new criteria for all-order accidental symmetries in terms of friends, and criteria for finite-order accidental symmetries in terms of friends ma non troppo. They allow us to verify and identify accidental symmetries more efficiently without computing the Hilbert series. We demonstrate the success of our new criteria by applying them to a variety of sample accidental symmetries, including the custodial symmetry in the Higgs sector of the Standard Model effective field theory.
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ATLAS Collaboration(Aad, G. et al), Aikot, A., Amos, K. R., Bouchhar, N., Cabrera Urban, S., Cantero, J., et al. (2025). Configuration, Performance, and Commissioning of the ATLAS b-jet Triggers for the 2022 and 2023 LHC data-taking periods. J. Instrum., 20(3), 002–45pp.
Abstract: In 2022 and 2023, the Large Hadron Collider produced approximately two billion hadronic interactions each second from bunches of protons that collide at a rate of 40 MHz. The ATLAS trigger system is used to reduce this rate to a few kHz for recording. Selections based on hadronic jets, their energy, and event topology reduce the rate to O(10) kHz while maintaining high efficiencies for important signatures resulting in b-quarks, but to reach the desired recording rate of hundreds of Hz, additional real-time selections based on the identification of jets containing b-hadrons (b-jets) are employed to achieve low thresholds on the jet transverse momentum at the High-Level Trigger. The configuration, commissioning, and performance of the real-time ATLAS b-jet identification algorithms for the early LHC Run 3 collision data are presented. These recent developments provide substantial gains in signal efficiency for critical signatures; for the Standard Model production of Higgs boson pairs, a 50% improvement in selection efficiency is observed in final states with four b-quarks or two b -quarks and two hadronically decaying.. -leptons.
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ATLAS Collaboration(Aad, G. et al), Aikot, A., Amos, K. R., Bouchhar, N., Cabrera Urban, S., Cantero, J., et al. (2025). Differential cross-section measurements of Higgs boson production in the H → τ+τ- decay channel in pp collisions at √s=13 TeV with the ATLAS detector. J. High Energy Phys., 03(3), 010–66pp.
Abstract: Differential measurements of Higgs boson production in the tau-lepton-pair decay channel are presented in the gluon fusion, vector-boson fusion (VBF), VH and t (t) over barH associated production modes, with particular focus on the VBF production mode. The data used to perform the measurements correspond to 140 fb(-1) of proton-proton collisions collected by the ATLAS experiment at the LHC. Two methods are used to perform the measurements: the Simplified Template Cross-Section (STXS) approach and an Unfolded Fiducial Differential measurement considering only the VBF phase space. For the STXS measurement, events are categorized by their production mode and kinematic properties such as the Higgs boson's transverse momentum (p(T)(H)), the number of jets produced in association with the Higgs boson, or the invariant mass of the two leading jets (m(jj)). For the VBF production mode, the ratio of the measured cross-section to the Standard Model prediction for m(jj) > 1.5 TeV and p(T)(H) > 200 GeV (p(T)(H) < 200 GeV) is 1.29(-0.34)(+0.39) (0.12(-0.33)(+0.34)). This is the first VBF measurement for the higher-p(T)(H) criteria, and the most precise for the lower-p(T)(H) criteria. The fiducial cross-section measurements, which only consider the kinematic properties of the event, are performed as functions of variables characterizing the VBF topology, such as the signed Delta phi(jj) between the two leading jets. The measurements have a precision of 30%-50% and agree well with the Standard Model predictions. These results are interpreted in the SMEFT framework, and place the strongest constraints to date on the CP-odd Wilson coefficient c(H (W) over tilde).
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Migueis, F., Casaña, J. V., Garcia-Fernandez, D., Hueso-Gonzalez, F., Llosa, G., Prieto, A. F., et al. (2025). Sensitivity of coaxial prompt gamma-ray monitoring in heterogeneous geometries: A Monte Carlo simulation study. Radiat. Phys. Chem., 232, 112639–11pp.
Abstract: Proton beams offer significant advantages over conventional radiotherapy due to their unique interaction with matter. Specifically, the ionization density caused by these beams is higher in a well-defined region (the Bragg peak) with a sharp decline in intensity beyond a specific depth. However, variations in proton range – often caused by changes in patient anatomy and morphology during treatment – can introduce uncertainties in dose distribution. To account for this, clinicians apply conservative margins, which limit the full potential of proton therapy. Efforts have been focused on developing proton range and dose distribution monitoring systems to reduce the need for large safety margins. These systems are based on detecting and analyzing the byproducts that result from the interaction between the proton beams and tissue. In this article, we focused specifically on a system that aims to detect photons called prompt gamma (PG) rays. We conducted Monte Carlo simulations of proton beams interacting with anthropomorphic phantoms of varying densities to simulate morphological changes. A single scintillation detector was positioned coaxially with the beam and behind the phantom to capture the emitted PG rays in each scenario. Our analysis focused on discrepancies in proton range that resulted from irradiating an anthropomorphic head phantom with varying brain tissue densities and detecting secondary particles resulting from these interactions. We observed potential correlations between gamma-ray signatures and variations in proton range and energy deposition, suggesting that this monitoring technique could be effective for real-world clinical applications.
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Gao, F., Miramontes, A. S., Papavassiliou, J., & Pawlowski, J. M. (2025). Heavy-light mesons from a flavour-dependent interaction. Phys. Lett. B, 863, 139384–8pp.
Abstract: We introduce a new framework for the physics of heavy-light mesons, whose key element is the effective incorporation of flavour-dependent contributions into the corresponding bound-state and quark gap equations. These terms originate from the fully-dressed quark-gluon vertices appearing in the kernels of these equations, and provide a natural distinction between “light” and “heavy” quarks. In this approach, only the classical form factor of the quark-gluon vertex is retained, and is evaluated in the so-called “symmetric” configuration. The standard Slavnov-Taylor identity links this form factor to the quark wave-function, allowing for the continuous transition from light to heavy quarks through the mere variation of the current quark mass in the gap equation. The method is used to compute the masses and decay constants of specific pseudoscalars and vector heavy-light systems, showing good overall agreement with both experimental data and lattice simulations.
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