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Dimitriou, A., Figueroa, D. G., Simakachorn, P., & Zaldivar, B. (2026). Cosmic string gravitational wave backgrounds at LISA: I. Signal survey, template reconstruction, and model comparison. J. Cosmol. Astropart. Phys., 05(5), 037–90pp.
Abstract: We present a catalog of gravitational wave background (GWB) signal templates from cosmic-string networks, based on relevant models proposed in the literature. We classify templates as conventional, based on standard cosmology and Nambu-Goto results (VOS and BOS), and beyond conventional, based on modifications of a) the loop number density (LRS, super, metastable, current-carrying strings), b) the expansion history (nonstandard cosmologies, extra degrees of freedom, either thermal or secluded), or c) the loop properties (birth length, power emission). Using the SBI package GWBackFinder: https://github.com/AndronikiDimitriou/GWBackFinder, we quantify the reconstruction precision of each signal by LISA, scanning over their parameter space, and performing model comparisons. For conventional signals, LISA reconstructs the tension G & micro; with an error less than or similar to 10% for G & micro; >= 5 & centerdot;10-15, which decreases down to 2-3% for G & micro; >= 10-12. BOS and VOS modelings become distinguishable confidently for G & micro; >= 5 & centerdot; 10-13. For beyond-conventional signals, we identify SNR and error-threshold intervals for each parameter, and determine (for few examples) the regions where they can be distinguished from conventional signals. Analogous quality reconstruction studies of cosmic-string GWBs, superimposed over leading astrophysical foregrounds in the LISA window, will be presented in a series of upcoming papers.
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ATLAS Collaboration(Aad, G. et al), Aikot, A., Amos, K. R., Bouchhar, N., Cabrera Urban, S., Cantero, J., et al. (2026). Search for signatures of electroweakinos with photons, jets, and large missing transverse momentum in √s=13 TeV pp collisions with the ATLAS detector. J. High Energy Phys., 04(4), 150–47pp.
Abstract: A search for final states characterised by at least one isolated high transverse-momentum photon, jets and large missing transverse momentum is presented. Such a final state might occur in gauge-mediated supersymmetric models where a pair of binos and higgsinos mix to form neutralinos, one of which decays into a photon plus a gravitino while the other decays into a Higgs boson, a Z boson or a photon, plus a gravitino. The search is performed using the full Run-2 data sample of 140 fb(-1) of root s = 13 TeV proton-proton collisions collected by the ATLAS detector at the Large Hadron Collider. No significant excess of events is observed above the Standard Model prediction and model-dependent exclusion limits at the 95% confidence level are set. These limits are interpreted in terms of the masses of gauginos, which are excluded up to 1.2 TeV depending on their branching ratios, and on their branching ratios as a function of their mass.
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ATLAS Collaboration(Aad, G. et al), Ahuja, S., Aikot, A., Amos, K. R., Bouchhar, N., Cabrera Urban, S., et al. (2026). Measurement of the top-quark mass using decays with a J/ψ meson at √s=13 TeV with the ATLAS detector. J. High Energy Phys., 04(4), 099–53pp.
Abstract: The top-quark mass is measured using top-quark decays producing an isolated lepton and J/psi meson reconstructed in its mu(+)mu(-) decay mode. The data sample was recorded with the ATLAS detector in proton-proton collisions at a centre-of-mass energy of root s = 13 TeV during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb(-1). The measurement is based on the invariant mass m(l mu(+)mu(-)) of the system made of the isolated lepton l from the W boson decay and the non-isolated mu(+)mu(-) pair from a J/psi decay of a b-hadron, exploiting its sensitivity to the top-quark mass. An unbinned maximum-likelihood fit to the m(l mu(+)mu(-)) distribution is performed to extract the top-quark mass. The top-quark mass is measured to be m(top) = 172.17 +/- 0.80 (stat) +/- 0.81 (syst) +/- 1.07 (recoil) GeV, with a total uncertainty of 1.56 GeV. The third uncertainty arises from changing the dipole parton shower gluon-recoil scheme used in top-quark decays.
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Sanz, V. (2026). Artificial intelligence and symmetries: Learning, encoding, and discovering structure in physical data. Int. J. Mod. Phys. A, , 2630008–27pp.
Abstract: Symmetries play a central role in physics, organizing dynamics, constraining interactions, and determining the effective number of physical degrees of freedom. In parallel, modern artificial intelligence methods have demonstrated a remarkable ability to extract low-dimensional structure from high-dimensional data through representation learning. This review examines the interplay between these two perspectives, focusing on the extent to which symmetry-induced constraints can be identified, encoded, or diagnosed using machine learning techniques. Rather than emphasizing architectures that enforce known symmetries by construction, we concentrate on data-driven approaches and latent representation learning, with particular attention to variational autoencoders. We discuss how symmetries and conservation laws reduce the intrinsic dimensionality of physical datasets, and how this reduction may manifest itself through self-organization of latent spaces in generative models trained to balance reconstruction and compression. We review recent results, including case studies from simple geometric systems and particle physics processes, and analyze the theoretical and practical limitations of inferring symmetry structure without explicit inductive bias.
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Zugec, P. (2026). Energy-differential measurement of the natC(n, p) and natC(n, d) reactions at the n_TOF facility at CERN. Phys. Rev. C, 113(4), 044621–22pp.
Abstract: Energy-differential cross section of the C-nat(n, p) and C-nat(n,d) reactions was measured at the neutron time-of-flight facility nTOF at CERN. The measurement was performed in the first experimental area (EAR1; flight path of 182.5 m). Two position-sensitive Delta E-E silicon telescopes were used. Two naturally occurring carbon isotopes, C-12 and C-13, contribute to the reactions on natural carbon, with the (n,p) reaction threshold at 13.7 MeV and the (n,d) threshold at 14.9 MeV (determined by the C-12 isotope for both reactions). This paper provides the details of the analysis leading to the final results published previously as a Letter. The cross-section results are reported up to 25 MeV. During the data analysis the population of the excited states in the daughter nuclei B-11, B-12, and B-13 had to be considered, requiring the adoption of the branching ratios and angular distributions of the emitted particles from an external source of information. TALYS-2.0 calculations were used as the main source and an in-depth analysis of the model-related uncertainties was performed. The nTOF results are largely inconsistent with the major evaluation libraries. On the other hand, an unexpected agreement is found with TALYS-2.0 calculations. Specifically, the obtained cross section for the (n,p) reaction is significantly higher than in the available evaluations, fully supporting the earlier finding from an integral measurement at n_TOF.
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