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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). Observation of structures in the J/ψ + ψ(2S) mass spectrum with the ATLAS detector. Phys. Rev. D, 113(11), 112015–30pp.
Abstract: A search for resonant structures in the J/psi + psi(2S) mass spectrum is performed using proton-proton collision data at root s = 13 TeV, corresponding to an integrated luminosity of 140 fb(-1), recorded by the ATLAS experiment at the LHC. The decay channels of J/psi + psi(2S) -> 4 μand J/psi + psi(2S) -> 4 μ+ 2 pi are analyzed. An excess near 6.9 GeV is observed in both channels with a combined significance of 8.9 sigma. No significant signal is observed near 7.2 GeV, and an upper limit on its yield relative to X(6900) is provided. A simultaneous fit with the di-J/psi channel is carried out under assumptions regarding the resonance interferences, yielding a ratio of the partial decay widths between the J/psi + psi(2S) and di-J/psi channels of 1.08 +/- 0.20(-0.17)(+0.40) for the resonance near 6.9 GeV.
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Real, D., Calvo, D., Burriel, I., Manzaneda, M., Moreno, A., & Parra, I. (2026). Design and Analysis of a Redundant, Low-Jitter Clocking System for White Rabbit Synchronization Switches. Appl. Sci.-Basel, 16(14), 7297–20pp.
Abstract: This work presents the design and validation of a redundant, low-jitter clock architecture for White Rabbit (WR) Switches, developed to meet the growing demand for sub-nanosecond synchronization in distributed scientific and industrial systems. WR relies on two high-purity clock signals (125 MHz and 124.992 MHz) to perform picosecond-resolution phase measurements using the DDMTD method; therefore, clock quality directly determines synchronization accuracy. The proposed architecture introduces a dual-path oscillator subsystem combining two independent low-phase-noise crystal oscillators with a secondary VCXO-based synthesizer, enabling deterministic automatic failover and eliminating the PLL-based frequency-generation stage used in legacy designs. Advanced signal- and power-integrity simulations were employed to optimize impedance control, PDN performance, and crosstalk behavior across the multilayer PCB. Measurements on the prototype demonstrate a reduction in integrated jitter from approximately 300 ps in previous implementations to 35-55 ps in the primary path, while failover events exhibit a worst-case switchover time of 10 & micro;s and a maximum phase hit below 150 ps. These results confirm that the redesigned architecture significantly enhances synchronization robustness and clock stability, providing a reliable foundation for large-scale deployments in high-energy physics, telecommunications, industrial automation, and other domains requiring ultra-precise timing.
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Ferreira, M. N., Miramontes, A. S., Morgado, J. M., & Papavassiliou, J. (2026). Light mesons in the symmetric-vertex approximation. Eur. Phys. J. C, 86(7), 858–19pp.
Abstract: We compute the spectrum of light mesons, composed by up, down, and strange quarks, using a symmetry-preserving approximation that permits the inclusion of fully-dressed quark-gluon vertices in the key dynamical equations. This method is characterized by the use of the standard symmetric kinematic configuration as a seed in the corresponding Schwinger-Dyson equation, yielding finally the full kinematic dependence of all eight form factors composing the transversely-projected quark-gluon vertex. The extension of this approach to the case of distinct nonvanishing current quark masses is discussed, and the compatibility with the fundamental Ward-Takahashi identities demonstrated. The corresponding Bethe-Salpeter kernel is composed by three different diagrammatic structures, which may be deduced from the attendant quark gap equation by applying the standard “cutting” rules. The masses of the light mesons are computed by first determining the eigenvalue of the Bethe-Salpeter equation as a function of Euclidean momenta, and then using the Schlessinger extrapolation method to determine the Minkowski momentum for which this eigenvalue becomes unity. The resulting meson masses are in good agreement with experimental values, and substantially improve upon predictions from the rainbow-ladder approximation.
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Pietri, S. et al, & Ayet, S. (2026). Production of isotopes near the heavy-element nucleosynthesis path at FRS. Phys. Lett. B, 880, 140729–6pp.
Abstract: Neutron-rich isotopes far from stability were produced and observed at the projectile Fragment Separator (FRS) of the GSI Helmholtzzentrum f & uuml;r Schwerionenforschung in the FAIR Phase-0 experimental program. The isotopes were produced in April 2020 in the fragmentation of a 1.05 GeV/nucleon 208Pb beam on a beryllium target. The experiment targeted the neutron-rich region near the N = 126 shell closure, a key area for understanding the astrophysical r-process, but largely unexplored due to the experimental challenges in producing such exotic nuclei. Within this work, we identified five isotopes which were not seen previously at FRS; 184Tm, 195Ta, 198W, 200Re, and 201Re – the latter located directly on the N = 126 line. These observations corroborate the extension of the nuclear chart and highlight the capabilities of the FRS and of in-flight fragmentation at relativistic energies in accessing this region.
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Franco-Patino, J. M., Garcia-Marcos, J., Belocchi, V., Barbaro, M. B., Co, G., & Gonzalez-Jimenez, R. (2026). Relativistic distorted-wave analysis of the missing-energy spectrum measured with monochromatic νμ-12C interactions at JSNS2. Phys. Rev. D, 114(1), 013006–11pp.
Abstract: Recently, the JSNS2 Collaboration measured for the first time the missing-energy distribution of 12C using a monochromatic neutrino beam coming from kaon decays at rest. In this work, we present the results of an analysis of this spectrum using the relativistic distorted-wave approach. A new parametrization of the spectral function for neutrons in 12C, which incorporates detailed information from (e; e0p) experiments with high missing-energy resolution, has been used. The role of the recoil of the residual nucleus, final-state interactions, and neutrino event generators are discussed.
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