Orrigo, S. E. A., Tain, J. L., Mont-Geli, N., Tarifeño-Saldivia, A., Fraile, L. M., Grieger, M., et al. (2022). Long-term evolution of the neutron rate at the Canfranc Underground Laboratory. Eur. Phys. J. C, 82(9), 814–11pp.
Abstract: We report results on the long-term variation of the neutron counting rate at the Canfranc Underground Laboratory, of importance for several low-background experiments installed there, including rare-event searches. The measurement campaign was performed employing the High Efficiency Neutron Spectrometry Array (HENSA) mounted in Hall A and lasted 412 live days. The present study is the first long-term measurement of the neutron rate with sensitivity over a wide range of neutron energies (from thermal up to 0.1 GeV and beyond) performed in any underground laboratory so far. Data on the environmental variables inside the experimental hall (radon concentration, air temperature, air pressure and humidity) were also acquired during all the measurement campaign. We have investigated for the first time the evolution of the neutron rate for different energies of the neutrons and its correlation with the ambient variables.
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Altakach, M. M., Lamba, P., Maselek, R., Mitsou, V. A., & Sakurai, K. (2022). Discovery prospects for long-lived multiply charged particles at the LHC. Eur. Phys. J. C, 82(9), 848–23pp.
Abstract: In this work, we aim to provide a comprehensive and largely model independent investigation on prospects to detect long-lived multiply charged particles at the LHC. We consider particles with spin 0 and 1/2, with electric charges in range 1 <= vertical bar Q/e vertical bar <= 8, which are singlet or triplet under SU(3)(c). Such particles might be produced as particle-antiparticle pairs and propagate through detectors, or form a positronium (quarkonium)-like bound state. We consider both possibilities and estimate lower mass bounds on new particles, that can be provided by ATLAS, CMS and Mol ',DAL experiments at the end of Run 3 and HL-LHC data taking periods. We find out that the sensitivities of ATLAS and CMS are generally stronger than those of MoEDAL at Run 3, while they may be competitive at HL-LHC for 3 less than or similar to vertical bar Q/e vertical bar less than or similar to 7 for all types of long-lived particles we consider.
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Oset, E., & Roca, L. (2022). Exotic molecular meson states of B(*) K(*) nature. Eur. Phys. J. C, 82(10), 882–9pp.
Abstract: We evaluate theoretically the interaction of the open bottom and strange systems (B) over bar (K) over bar, (B) over bar * (K) over bar, (B) over bar (K) over bar * and (B) over bar* (K) over bar* to look for possible bound states which could correspond to exotic non-quark-antiquark mesons since they would contain at least one b and one s quarks. The s-wave scattering matrix is evaluated implementing unitarity by means of the Bethe-Salpeter equation, with the potential kernels obtained from contact and vector meson exchange mechanisms. The vertices needed are supplied from Lagrangians derived from suitable extensions of the hidden gauge symmetry approach to the bottom sector. We find poles below the respective thresholds for isospin 0 interaction and evaluate the widths of the different obtained states by including the main sources of imaginary part, which are the B *-> B gamma decay in the (B) over bar * (K) over bar channels, the K *-> K pi in the channels involving a K *, plus the box diagrams with (B) over bar (K) over bar and (B) over bar * (K) over bar intermediate states for the (B) over bar * (K) over bar * channels.
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Flavour Lattice Averaging Group(Aoki, Y. et al), Hernandez, P., & Ramos, A. (2022). FLAG Review 2021. Eur. Phys. J. C, 82(10), 869–296pp.
Abstract: We review lattice results related to pion, kaon, D-meson, B-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More specifically, we report on the determination of the light-quark masses, the form factor f(+) (0) arising in the semileptonic K -> pi transition at zero momentum transfer, as well as the decay constant ratio Alf, and its consequences for the CKM matrix elements V-us and V-ud. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of SU(2)(L) x SU(2)(R) and SU(3)(L) x SU(3)(R) Chiral Perturbation Theory. We review the determination of the B-K parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. For the heavy-quark sector, we provide results for m(c) and m(b) as well as those for the decay constants, form factors, and mixing parameters of charmed and bottom mesons and baryons. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. We review the status of lattice determinations of the strong coupling constant alpha(s). We consider nucleon matrix elements, and review the determinations of the axial, scalar and tensor bilinears, both isovector and flavor diagonal. Finally, in this review we have added a new section reviewing determinations of scale-setting quantities.
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Rahaman, U., & Raut, S. K. (2022). On the tension between the latest NO nu A and T2K data. Eur. Phys. J. C, 82(10), 910–15pp.
Abstract: The latest data from the T2K and NO nu A experiments show a tension in their preferred values of the oscillation parameters. In this work, we try to identify the source of the tension between the data from these two experiments. An analysis of their data from various channels (individually, and combined) shows that the tension arises primarily from the nu(e) appearance data, and is compounded by the (nu) over bar (mu) disappearance data. We provide an explanation for the tension based on parameter degeneracies. Apart from the analysis with the standard matter effect, we also analyse the data with the vacuum oscillation hypothesis. We find that vacuum oscillations fit the data as well as matter effects do; and also reduce the tension between the two experiments. We have also done a study of the future run of NO nu A, T2K and DUNE in the context of establishing this tensionwith higher statistical significance.
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