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Bussone, A., Conigli, A., Frison, J., Herdoiza, G., Pena, C., Preti, D., et al. (2026). Hadronic physics from a Wilson fermion mixed-action approach: setup and scale setting. Eur. Phys. J. C, 86(5), 577–68pp.
Abstract: We introduce a lattice QCD mixed action approach that employs Wilson-type quarks in the sea and valence sectors. The sea sector is based on gauge ensembles with Nf=2+1 flavours of non-perturbatively O(a)-improved Wilson fermions generated by the Coordinated Lattice Simulations (CLS) initiative. The parameter space of the considered ensembles encompasses five values of the lattice spacing, a range of pion masses extending down to the physical point, and large physical volumes. In the valence sector, we employ Wilson twisted-mass fermions at maximal twist, using the same massless Wilson-Dirac operator in both the sea and valence sectors. We describe the strategy applied for the required matching of the sea and valence quark masses along the target renormalised chiral trajectory. A precise universality test is then conducted by comparing the continuum-limit results of the mixed-action approach and of the unitary setup, in which the same Wilson fermion regularisation is employed in the sea and in the valence. As a key application, we conduct a scale setting procedure based on lattice determinations of the masses and decay constants of the pion and kaon, as well as the gradient flow scale t0. The scale setting can consequently be performed in three distinct ways, utilising the unitary setup, the mixed action approach, and their combination. We observe that the latter combination results in enhanced control of the systematic uncertainties, thereby yielding a precise determination of the physical value of t0.
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HAWC Collaboration(Albert, A. et al), & Coutiño de Leon, S. (2026). Search for Signatures of Dark Matter Annihilation in the Galactic Center with HAWC. Phys. Rev. Lett., 136(19), 191001–6pp.
Abstract: We conduct an indirect dark matter (DM) search in the vicinity of the Galactic Center, focusing on a square region within +/- 9 degrees in Galactic longitude and latutide, using 2865 days of data (similar to 8 yr) from the High-Altitude Water Cherenkov (HAWC) Observatory. We explore DM particles within the weakly interacting massive particles framework with masses from 1 TeV to 10 PeV. Analyzing three annihilation channels (b (b) over bar, tau(+)tau(-), W+W-) and three density profiles (Navarro-Frenk-White, Einasto, Burkert), we find no significant excess and set 95% CL upper limits on the velocity-weighted annihilation cross section. Our results provide the first constraints on DM particles well above 100 TeV using gamma-ray data from the vicinity of the Galactic Center, with the strongest limits O(10(-24)) cm(3)/s, from the tau(+)tau(-) channel and the Einasto profile.
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Cornet-Gomez, F., Miralles, V., Miralles Lopez, M., Moreno Llacer, M., & Vos, M. (2026). Sensitivity analysis of the top-quark sector. Eur. Phys. J. Plus, 141(5), 596–6pp.
Abstract: We study the sensitivity of current and future collider observables to top-quark SMEFT operators through a one-operator-at-a-time analysis. Using data from the Tevatron, LEP, and LHC Run 2, as well as projections for the HL-LHC and future lepton colliders, we identify the measurements that provide the strongest individual constraints. This approach clarifies the role of specific observables in the top-quark SMEFT program and highlights the significant improvement in sensitivity expected at future facilities.
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Liang, W. H., Hu, Z. R., & Oset, E. (2026). The B+(0) → D¯ 0(-) D∗s0(2317)+ decays and the molecular structure of D∗s0(2317). Eur. Phys. J. A, 62(5), 104–9pp.
Abstract: We have conducted a study of the B+(0) -> D & strns;D-0(-)(s0)& lowast;(2317)(+) reactions from the perspective that the D(s0)(& lowast;)0(2317) resonance is a molecular state of the DK and D-s eta components. We have followed a method to evaluate the branching fractions obtaining information from the experimental data on the B+ -> (DK+)-K-& strns;-K-0 D-0, B+ -> (DKD+)-K-& strns;0-D-0, B-0 -> D-K (+) D-0, B-0 -> (D-KD+)-D-0 reactions, which have the (DK +)-K-0 and (D+K0) pairs in the final state. The approach concentrates the dynamics of the weak process in the branching ratios of these reactions and pays attention to the propagation of the DK components and their strong interaction to form the D-s0(& lowast;)(2317) resonance. By means of two free parameters, we are able to describe these six rates, showing consistency with the molecular picture of the D-s0(& lowast;)(2317) state.
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KM3NeT Collaboration(Adriani, O. et al), Alves Garre, S., Bariego-Quintana, A., Calvo, D., Cecchini, V., Garcia Soto, A., et al. (2026). On the Potential Galactic Origin of the Ultra-high-energy Event KM3-230213A. Astrophys. J., 1003(2), 157–12pp.
Abstract: The KM3NeT observatory detected the most energetic neutrino candidate ever observed, with an energy between 72 PeV and 2.6 EeV at the 90% confidence level. The observed neutrino is likely of cosmic origin. In this article, it is investigated if the neutrino could have been produced within the Milky Way. Considering the low fluxes of the Galactic diffuse emission at these energies, the lack of a nearby potential Galactic particle accelerator in the direction of the event, and the difficulty of accelerating particles to such high energies in Galactic systems, we conclude that if the event is indeed cosmic, it is most likely of extragalactic origin.
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