Song, J., Liang, W. H., & Oset, E. (2025). Determination of the K+K0 scattering length and effective range from the D+→K0π+η reaction. Eur. Phys. J. C, 85(5), 513–9pp.
Abstract: We study the scattering parameters of the K+K0 system through the analysis of the D+-> K0 pi+eta reaction, aiming at determining the scattering length a and effective range r0 of the K+K0 interaction. These parameters are extracted by analyzing and fitting the mass distributions of the pairs in the final K0 pi+eta state. To ensure the reliability of the results, we apply resampling techniques to evaluate statistical uncertainties and improve the precision of the scattering parameters. The obtained results are compared with previous theoretical predictions and experimental data, providing new insights into the K+K0 interaction at low energies.
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Maluf, R. V., Silva, J. E. G., Almeida, C. A. S., & Olmo, G. J. (2025). Perturbative solutions for compact objects in (2+1)-dimensional Bopp-Podolsky electrodynamics. Eur. Phys. J. C, 85(5), 594–8pp.
Abstract: We investigate the space-time geometry generated by compact objects in (2+1)-dimensional Bopp-Podolsky electrodynamics. Inspired by previous studies where the Bopp-Podolsky field acts as a source for spherically symmetric solutions, we revisit this question within the lower-dimensional (2+1) framework. Using a perturbative approach, we derive a charged BTZ-like black hole solution and compute corrections up to second order in a perturbative expansion valid far from the horizon. Our analysis suggests that the near-horizon and inner structure of the solution remain unaltered, indicating that no new non-black hole objects emerge in this regime. In particular, we do not find evidence of wormhole solutions in the (2+1)-dimensional version of this theory.
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NEXT Collaboration(Dey, E. et al), Ayet, A., Byrnes, N., Carcel, S., Kellerer, F., Lopez-March, N., et al. (2025). Ion transport on phased radiofrequency carpets in xenon gas. Eur. Phys. J. C, 85(6), 688–15pp.
Abstract: We present the design and performance of a four-phased radiofrequency (RF) carpet system for ion transport between 200-600 mbar, significantly higher than previously demonstrated RF carpet applications. The RF carpet, designed with a 160 mu\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\upmu $$\end{document}m pitch, is applied to the lateral collection of ions in xenon at pressures up to 600 mbar. We demonstrate transport efficiency of caesium ions across varying pressures, and compare with microscopic simulations made in the SIMION package. The novel use of an N-phased RF carpet can achieve ion levitation and controlled lateral motion in a denser environment than is typical for RF ion transport in gases. This feature makes such carpets strong candidates for ion transport to single ion sensors envisaged for future neutrinoless double-beta decay experiments in xenon gas.
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Abramowicz, H., Almanza Soto, M., Benhammou, Y., Elad, M., Firlej, M., Fiutowski, T., et al. (2025). Novel silicon and GaAs sensors for compact sampling calorimeters. Eur. Phys. J. C, 85(6), 684–13pp.
Abstract: Two samples of silicon pad sensors and two samples of GaAs sensors are studied in an electron beam with 5 GeV energy from the DESY-II test-beam facility. The sizes of the silicon and GaAs sensors are about 9 x\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times $$\end{document} 9 cm2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {cm}<^>2$$\end{document} and 5 x\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times $$\end{document} 8 cm2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {cm}<^>2$$\end{document}, respectively. The thickness is 500 μm for both the silicon and GaAs sensors. The pad size is about 5 x\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times $$\end{document} 5 mm2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {mm}<^>2$$\end{document}. The sensors are foreseen to be used in a compact electromagnetic sampling calorimeter. The readout of the pads is done via traces connected to the pads and the front-end ASICs at the edges of the sensors. For the silicon sensors, copper traces on a Kapton foil are connected to the sensor pads with conducting glue. The pads of the GaAs sensors are connected to bond-pads via aluminium traces on the sensor substrate. The readout is based on a dedicated front-end ASIC, called FLAME. Pre-processing of the raw data and deconvolution is performed with FPGAs. The whole system is orchestrated by a Trigger Logic Unit. Results are shown for the signal-to-noise ratio, the homogeneity of the response, edge effects on pads, cross talk and wrongly assigned signals due to the readout traces.
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Li, H. P., Liang, W. H., Xiao, C. W., Xie, J. J., & Oset, E. (2025). Determination of the binding and DK probability of the Ds0*(2317) from the (DK)- mass distributions in Λb→Λ(DK)- decays. Eur. Phys. J. C, 85(6), 616–9pp.
Abstract: We study the Lambda b ->Lambda cD0K- and Lambda b ->Lambda cD-K0 decays which proceed via a Cabibbo and Nc favored process of external emission, and we determine the D0K- and D-K0 mass distributions close to the DK threshold. For this, we use the tree level contribution plus the rescattering of the meson-meson components, using the extension of the local hidden gauge approach to the charm sector that produces the Ds0*(2317) resonance. We observe a large enhancement of the mass distributions close to threshold due to the presence of this resonance below threshold. Next we undertake the inverse problem of extracting the maximum information on the interaction of the DK channels from these distributions, and using the resampling method we find that from these data one can obtain precise values of the scattering lengths and effective ranges, the existence of an I=0 bound state with a precision of about 4MeV in the mass, plus the DK molecular probability of this state with reasonable precision. Given the fact that the Lambda b ->Lambda cD0K- decay is already measured by the LHCb collaboration, it is expected that in the next runs with more statistics of the decay, these mass distributions can be measured with precision and the method proposed here can be used to determine the nature of the Ds0*(2317), which is still an issue of debate.
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