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NEXT Collaboration(Martinez-Lema, G. et al), Ayet, S., Cid, M., Cortes-Parra, C., Kellerer, F., Lopez-March, N., et al. (2026). First results of the NEXT-100 detector using 83mKr decays. Eur. Phys. J. C, 86(7), 739–12pp.
Abstract: The NEXT collaboration is investigating the double beta decay of 136Xe using high-pressure gas electroluminescent time projection chambers, which provide excellent energy resolution together with a robust topological signature. Operating at the Laboratorio Subterr & aacute;neo de Canfranc (LSC) and building on the success of the NEXT-White detector, the NEXT-100 apparatus began commissioning in May 2024 and started operation with xenon at a pressure of 4 bar in October 2024. We report here the first results obtained with NEXT-100 using low-energy calibration data from 83mKr decays, which allow mapping of the detector response in the active volume and monitoring of its stability over time. After homogenizing the light response, we achieve an energy resolution of 4.37% FWHM at 41.5 keV for 83mKr point-like energy deposits contained in a radius of 425 mm. In a fiducial region representing the operating conditions of NEXT-100 at 10 bar we obtain an improved energy resolution of 4.16% FWHM. These results are in good agreement with that obtained in NEXT-White, and an E-1/2 extrapolation to Q beta beta yields an energy resolution close to 0.5% FWHM, well below the 1% FWHM design target.
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Kuncinas, A., Osland, P., & Rebelo, M. N. (2026). Systematic analysis of 3HDM symmetries. Phys. Rev. D, 113(11), 115054–41pp.
Abstract: Symmetries play a crucial role in shaping the structure and predictions of multi-Higgs-doublet models. In three-Higgs-doublet models considerable effort has been put into classifying possible symmetry groups and the conditions for their realization, yet the completeness of existing classifications remains an open question. In this work, we revisit the problem of identifying realizable symmetries by reexamining conventional Higgs family and general CP transformations from an alternative perspective. Our analysis identifies certain limitations in previous approaches and introduces a clearer, more systematic framework for model builders. We expand our classification by investigating more generalized symmetry structures- the recently identified “GOOFy” transformations, which act nontrivially on the Higgs doublets and their conjugates. Our analysis consolidates known results, uncovers previously overlooked structures, and expands the set of symmetries in three-Higgs-doublet models, offering both a clearer theoretical foundation and a practical reference for symmetry-based model building.
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Song, J., Li, Y. Y., Bayar, M., & Oset, E. (2026). a0(980) and f0(980) excitation in the D plus → π plus ηη decay. Phys. Rev. D, 113(11), 114039–15pp.
Abstract: We have made a thorough study of the D+ -> c+ririreaction, recently measured by the Beijing Spectrometer III Collaboration, which shows an abnormal strength at high invariant masses in the cri mass distribution. We studied in detail the triangle mechanism and the f0(1370) excitation modes that have been suggested to explain this abnormal feature, and concluded that they are too small to have any important role in the solution to that problem. We have also studied other possible solutions, evaluating the contribution of excitations of other f0, a0 and f2 resonances, and reached the same conclusion. Unexpectedly, the solution to the problem is found considering the f0(980) excitation, with the f0(980) decaying to two ri, which is tied to the a0(980) production, and well under control. At the same time, the consideration of the f0(980) excitation solves another nonreported problem, which is the riri mass distribution that comes when only the a0(980) resonance is allowed to be excited, which produces a large deficiency at low invariant masses compared with experiments.
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Barenboim, G. (2026). The noise of vacuum. J. Cosmol. Astropart. Phys., 06(6), 080–32pp.
Abstract: We investigate the evolution of primordial cosmological perturbations in a vacuum decay model where de Sitter space transitions to radiation domination through quantum-thermal decay processes. Unlike standard inflation, this framework generates curvature perturbations through stochastic noise from vacuum decay rather than quantum fluctuations of an inflaton field. We derive the stochastic differential equation governing the curvature perturbation R(t) and show that any horizon crossing is brief and does not constitute the primary mechanism for perturbation generation. Scale dependence emerges from spatial correlations in the noise rather than horizon crossing dynamics. The model naturally addresses the horizon and flatness problems through initial thermal equilibrium in de Sitter space and predicts zero tensor-to-scalar ratio. We demonstrate that spatially correlated noise can generate observationally viable spectral tilts while maintaining Gaussian statistics.
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Mitsou, V. A., Staelens, M., & Hung, P. Q. (2026). Signatures and probes of mirror mesons at colliders. Eur. Phys. J.-Spec. Top., , 15pp.
Abstract: The experimental confirmation of non-vanishing neutrino masses at the sub-eV range poses a challenge for the (otherwise successful) Standard Model (SM). The EW- nu R model, which gives a solution to this problem via a seesaw mechanism with non-sterile right-handed neutrinos at the electroweak scale, contains mirror fermion doublets and singlets with opposite chirality assignments under the same SUW(2) gauge symmetry. It also features a viable dark-matter candidate and proposes a solution to the strong CP problem. The (electroweak scale) mirror quarks (leptons) decay to SM quarks (leptons) plus very light neutral scalars, giving final states with jets or leptons, scalar mesons and missing momentum. In this paper, we review the signatures through which these mirror particles can be probed at colliders such as the Large Hadron Collider. Emphasis is given to long-lived mirror particles, depending on the associated Yukawa couplings, that can give rise to observable displaced leptons and jets, and heavy hadrons.z
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