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n_TOF Collaboration(Garcia-Infantes, F. et al), Babiano-Suarez, V., Balibrea-Correa, J., Casanovas-Hoste, A., Domingo-Pardo, C., Ladarescu, I., et al. (2024). Measurement of the 176Yb(n,γ) cross section at the n_TOF facility at CERN. Phys. Rev. C, 110(6), 064619–16pp.
Abstract: Background: The Yb-176(n, gamma)Yb-177 -> 177Lu reaction is of interest in nuclear medicine as it is the preferred production route for 177Lu. This radioisotope has seen a very fast growth of usage in nuclear medicine in recent years due to its outstanding properties. New data on this reaction could provide useful information for production at new facilities. Purpose: We aim to resolve resonances in the Yb-176(n, gamma)Yb-177 reaction for the first time. Previous capture measurement provided data at thermal point and encompassed integral measurements in the range from 3 keV to 1 MeV, where three time-of-flight measurements are available, but with low resolution to resolve the resonances. Transmission measurements from the 1970s resolved and analyzed some resonances. Method: We measure the neutron capture cross section of Yb-176(n, gamma)Yb-177 by means of the time-of-flight technique at the Experimental Area 1 of the n_TOF facility at CERN using an enriched (Yb2O3)-Yb-176 sample and an array of four C6D6 liquid scintillation detectors. Results: We have resolved 164 resonances up to 21 keV, including 96 new ones. We also provide new capture experimental data from 90 eV to 3 keV, and we extend the resolved resonance region up to 21 keV. In addition, resonance decay widths, Gamma(gamma) and Gamma(n), are provided for all resonances together with resonance energies. Conclusions: The Yb-176(n, gamma) Yb-177 reaction has been measured, providing resonance parameters for the first time from a few eV to 21 keV. The analysis of the resonances has been carried out and compared with previous works and existing libraries, revealing discrepancies due to the new information on Gamma(gamma) parameters. Our results are consistent with the Gamma(n) parameters obtained in transmission measurements.
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Arbelaez, C., Cottin, G., Helo, J. C., Hirsch, M., & de Melo, T. B. (2025). Long-lived particle phenomenology in one-loop neutrino mass models with dark matter. J. High Energy Phys., 02(2), 049–22pp.
Abstract: Neutrino masses and dark matter (DM) might have a common origin. The scotogenic model can be considered the proto-type model realizing this idea, but many other variants exist. In this paper we explore the phenomemology of a particular DM neutrino mass model, containing a triplet scalar. We calculate the relic density and check for constraints from direct detection experiments. The parameter space of the model, allowed by these constraints, contains typically a long-lived or quasi-stable doubly charged scalar, that can be searched for at the LHC. We reinterpret existing searches to derive limits on the masses of the scalars of the model and estimate future sensitivities in the high-luminosity phase of the LHC. The searches we discuss can serve to constrain also many other 1-loop neutrino mass models.
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ATLAS Collaboration(Aad, G. et al), Aikot, A., Amos, K. R., Bouchhar, N., Cabrera Urban, S., Cantero, J., et al. (2024). Search for neutral long-lived particles that decay into displaced jets in the ATLAS calorimeter in association with leptons or jets using pp collisions at √s=13 TeV. J. High Energy Phys., 11(11), 036–52pp.
Abstract: A search for neutral long-lived particles (LLPs) decaying in the ATLAS hadronic calorimeter using 140 fb(-1) of proton-proton collisions at root s = 13TeV delivered by the LHC is presented. The analysis is composed of three channels. The first targets pair-produced LLPs, where at least one LLP is produced with sufficiently low boost that its decay products can be resolved as separate jets. The second and third channels target LLPs respectively produced in association with a W or Z boson that decays leptonically. In each channel, different search regions target different kinematic regimes, to cover a broad range of LLP mass hypotheses and models. No excesses of events relative to the background predictions are observed. Higgs boson branching fractions to pairs of hadronically decaying neutral LLPs larger than 1% are excluded at 95% confidence level for proper decay lengths in the range of 30 cm to 4.5m depending on the LLP mass, a factor of three improvement on previous searches in the hadronic calorimeter. The production of long-lived dark photons in association with a Z boson with cross-sections above 0.1 pb is excluded for dark photon mean proper decay lengths in the range of 20 cm to 50 m, improving previous ATLAS results by an order of magnitude. Finally, long-lived photo-phobic axion-like particle models are probed for the first time by ATLAS, with production cross-sections above 0.1 pb excluded in the 0.1mm to 10m range.
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Real, D., Ballester, J., Calvo, D., Manzaneda, M., Moreno, A., Albiol, F., et al. (2025). Readout System for Multipurpose Real-Time and Portable Spectrometer. Electronics, 14(3), 506–21pp.
Abstract: A ready-to-use spectrometer-based product, which focuses on data acquisition using a BeagleBone board and a Hamamatsu C12666MA spectrometer module, is presented. The device meets stringent requirements, including the ability to measure the visible light spectrum over a wide range of intensities, being compact and lightweight, and having customizable electronics to suit different application needs. The system's primary component is a Hamamatsu C12666MA spectrometer module with a measurement range of 341 nm to 780 nm, which is supplemented by supporting electronics such as a microcontroller and an analog-to-digital converter. The development encompasses hardware design, the fabrication of a control board, and software development for spectral acquisition and visualization. The software controls the spectral measurement process and facilitates data processing and analysis. The results demonstrate that the designed system can accurately capture spectra and fulfill the specified requirements. Additionally, this work investigates and evaluates the potential migration of the data acquisition system to Field-Programmable Gate Array technology. Such a migration offers several advantages, including real-time processing, parallel data handling capabilities, reduced latency, and greater flexibility in adapting to various spectrometer configurations, as well as the possibility to work in a synchronized way with other devices. These improvements would significantly expand the system's potential applications in real-time spectroscopy and other demanding optical measurement tasks. The proposed system thus provides a foundation for future enhancements, which could exploit Field-Programmable Gate Array technology, potentially revolutionizing the efficiency and application scope of portable spectrometry devices.
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Jiang, J. Q., Giare, W., Garzai, S., Dainotti, M. G., Di Valentino, E., Mena, O., et al. (2025). Neutrino cosmology after DESI: tightest mass upper limits, preference for the normal ordering, and tension with terrestrial observations. J. Cosmol. Astropart. Phys., 01(1), 153–43pp.
Abstract: The recent DESI Baryon Acoustic Oscillation measurements have led to tight upper limits on the neutrino mass sum, potentially in tension with oscillation constraints requiring Sigma m(nu) greater than or similar to 0.06 eV. Under the physically motivated assumption of positive Sigma m(nu), we study the extent to which these limits are tightened by adding other available cosmological probes, and robustly quantify the preference for the normal mass ordering over the inverted one, as well as the tension between cosmological and terrestrial data. Combining DESI data with Cosmic Microwave Background measurements and several late-time background probes, the tightest 2 sigma limit we find without including a local H-0 prior is Sigma m(nu) < 0.05 eV. This leads to a strong preference for the normal ordering, with Bayes factor relative to the inverted one of 46.5. Depending on the dataset combination and tension metric adopted, we quantify the tension between cosmological and terrestrial observations as ranging between 2.5 sigma and 5 sigma. These results are strenghtened when allowing for a time-varying dark energy component with equation of state lying in the physically motivated non-phantom regime, w(z) >= -1, highlighting an interesting synergy between the nature of dark energy and laboratory probes of the mass ordering. If these tensions persist and cannot be attributed to systematics, either or both standard neutrino (particle) physics or the underlying cosmological model will have to be questioned.
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