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LISA Cosmology Working Group(Bartolo, N. et al), & Figueroa, D. G. (2022). Probing anisotropies of the Stochastic Gravitational Wave Background with LISA. J. Cosmol. Astropart. Phys., 11, 009–65pp.
Abstract: We investigate the sensitivity of the Laser Interferometer Space Antenna (LISA) to the anisotropies of the Stochastic Gravitational Wave Background (SGWB). We first discuss the main astrophysical and cosmological sources of SGWB which are characterized by anisotropies in the GW energy density, and we build a Signal-to-Noise estimator to quantify the sensitivity of LISA to different multipoles. We then perform a Fisher matrix analysis of the prospects of detectability of anisotropic features with LISA for individual multipoles, focusing on a SGWB with a power-law frequency profile. We compute the noise angular spectrum taking into account the specific scan strategy of the LISA detector. We analyze the case of the kinematic dipole and quadrupole generated by Doppler boosting an isotropic SGWB. We find that beta Omega(GW) similar to 2 x 10(-11) is required to observe a dipolar signal with LISA. The detector response to the quadrupole has a factor similar to 10(3) beta relative to that of the dipole. The characterization of the anisotropies, both from a theoretical perspective and from a map-making point of view, allows us to extract information that can be used to understand the origin of the SGWB, and to discriminate among distinct superimposed SGWB sources.
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ANTARES Collaboration(Albert, A. et al), Alves, S., Calvo, D., Carretero, V., Gozzini, R., Hernandez-Rey, J. J., et al. (2022). Search for non-standard neutrino interactions with 10 years of ANTARES data. J. High Energy Phys., 07(7), 048–22pp.
Abstract: Non-standard interactions of neutrinos arising in many theories beyond the Standard Model can significantly alter matter effects in atmospheric neutrino propagation through the Earth. In this paper, a search for deviations from the prediction of the standard 3-flavour atmospheric neutrino oscillations using the data taken by the ANTARES neutrino telescope is presented. Ten years of atmospheric neutrino data collected from 2007 to 2016, with reconstructed energies in the range from similar to 16 GeV to 100 GeV, have been analysed. A log-likelihood ratio test of the dimensionless coefficients epsilon(mu tau) and epsilon(tau tau) – epsilon(mu mu) does not provide clear evidence of deviations from standard interactions. For normal neutrino mass ordering, the combined fit of both coefficients yields a value 1.7 sigma away from the null result. However, the 68% and 95% confidence level intervals for epsilon(mu tau) and epsilon(tau tau) – epsilon(mu mu), respectively, contain the null value. Best fit values, one standard deviation errors and bounds at the 90% confidence level for these coefficients are given for both normal and inverted mass orderings. The constraint on epsilon(mu tau) is among the most stringent to date and it further restrains the strength of possible non-standard interactions in the μ- tau sector.
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Balaudo, A., Calore, F., De Romeri, V., & Donato, F. (2024). NAJADS: a self-contained framework for the direct determination of astrophysical J-factors. J. Cosmol. Astropart. Phys., 02(2), 001–33pp.
Abstract: Cosmological simulations play a pivotal role in understanding the properties of the dark matter (DM) distribution in both galactic and galaxy -cluster environments. The characterization of DM structures is crucial for informing indirect DM searches, aiming at the detection of the annihilation (or decay) products of DM particles. A fundamental quantity in these analyses is the astrophysical J -factor. In the DM phenomenology community, J -factors are typically computed through the semi -analytical modelling of the DM mass distribution, which is affected by large uncertainties. With the scope of addressing and possibly reducing these uncertainties, we present NAJADS, a self-contained framework to derive the DM J -factor directly from the raw simulations data. We show how this framework can be used to compute all -sky maps of the J -factor, automatically accounting for the complex 3D structure of the simulated halos and for the boosting of the signal due to the density fluctuations along the line of sight. After validating our code, we present a proof -of -concept application of NAJADS to a realistic halo from the IllustrisTNG suite, and exploit it to make a thorough comparison between our numerical approach and traditional semi -analytical methods. JCAP02(2024)001
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Mandic, I., Cindro, V., Debevc, J., Gorisek, A., Hiti, B., Kramberger, G., et al. (2022). Study of neutron irradiation effects in Depleted CMOS detector structures. J. Instrum., 17(3), P03030–13pp.
Abstract: In this paper the results of Edge-TCT and I-V measurements with passive test structures made in LFoundry 150 nm HV-CMOS process on p-type substrates with different initial resistivities ranging from 0.5 to 3 k Omega cm are presented. Samples were irradiated with reactor neutrons up to a fluence of 2.10(15) n(eq)/cm(2). The depletion depth was measured with Edge-TCT. The effective space charge concentration N-eff was estimated from the dependence of the depletion depth on bias voltage and studied as a function of neutron fluence. The dependence of N-eff on fluence changes with initial acceptor concentration in agreement with other measurements with p-type silicon. A long term accelerated annealing study of N-eff and detector current up to 1280 minutes at 60 degrees C was made. It was found that N-eff and current in reverse biased detector behave as expected for irradiated silicon.
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LHCb Collaboration(Aaij, R. et al), Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., & Ruiz Vidal, J. (2022). Identification of charm jets at LHCb. J. Instrum., 17(2), P02028–23pp.
Abstract: The identification of charm jets is achieved at LHCb for data collected in 2015-2018 using a method based on the properties of displaced vertices reconstructed and matched with jets. The performance of this method is determined using a dijet calibration dataset recorded by the LHCb detector and selected such that the jets are unbiased in quantities used in the tagging algorithm. The charm-tagging efficiency is reported as a function of the transverse momentum of the jet. The measured efficiencies are compared to those obtained from simulation and found to be in good agreement.
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Diaz-Morcillo, A., Barcelo, J. M. G., Guerrero, A. J. L., Navarro, P., Gimeno, B., Cuneáis, S. A., et al. (2022). Design of New Resonant Haloscopes in the Search for the Dark Matter Axion: A Review of the First Steps in the RADES Collaboration. Universe, 8(1), 5–22pp.
Abstract: With the increasing interest in dark matter axion detection through haloscopes, in which different international groups are currently involved, the RADES group was established in 2016 with the goal of developing very sensitive detection systems to be operated in dipole magnets. This review deals with the work developed by this collaboration during its first five years: from the first designs-based on the multi-cavity concept, aiming to increase the haloscope volume, and thereby improve sensitivity-to their evolution, data acquisition design, and finally, the first experimental run. Moreover, the envisaged work within RADES for both dipole and solenoid magnets in the short and medium term is also presented.
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Briz, J. A., Nerio, A. N., Ballesteros, C., Borge, M. J. G., Martinez, P., Perea, A., et al. (2022). Proton Radiographs Using Position-Sensitive Silicon Detectors and High-Resolution Scintillators. IEEE Trans. Nucl. Sci., 69(4), 696–702.
Abstract: Proton therapy is a cancer treatment technique currently in growth since it offers advantages with respect to conventional X-ray and gamma-ray radiotherapy. In particular, better control of the dose deposition allowing to reach higher conformity in the treatments causing less secondary effects. However, in order to take full advantage of its potential, improvements in treatment planning and dose verification are required. A new prototype of proton computed tomography scanner is proposed to design more accurate and precise treatment plans for proton therapy. Our prototype is formed by double-sided silicon strip detectors and scintillators of LaBr3(Ce) with high energy resolution and fast response. Here, the results obtained from an experiment performed using a 100-MeV proton beam are presented. Proton radiographs of polymethyl methacrylate (PMMA) samples of 50-mm thickness with spatial patterns in aluminum were taken. Their properties were studied, including reproduction of the dimensions, spatial resolution, and sensitivity to different materials. Structures of up to 2 mm are well resolved and the sensitivity of the system was enough to distinguish the thicknesses of 10 mm of aluminum or PMMA. The spatial resolution of the images was 0.3 line pairs per mm (MTF-10%). This constitutes the first step to validate the device as a proton radiography scanner.
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LHCb Collaboration(Aaij, R. et al), Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., & Ruiz Vidal, J. (2022). Centrality determination in heavy-ion collisions with the LHCb detector. J. Instrum., 17(5), P05009–31pp.
Abstract: The centrality of heavy-ion collisions is directly related to the created medium in these interactions. A procedure to determine the centrality of collisions with the LHCb detector is implemented for lead-lead collisions root s(NN) = 5 TeV and lead-neon fixed-target collisions at root s(NN) = 69 GeV. The energy deposits in the electromagnetic calorimeter are used to determine and define the centrality classes. The correspondence between the number of participants and the centrality for the lead-lead collisions is in good agreement with the correspondence found in other experiments, and the centrality measurements for the lead-neon collisions presented here are performed for the first time in fixed-target collisions at the LHC.
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Hiti, B., Cindro, V., Gorisek, A., Franks, M., Marco-Hernandez, R., Kramberger, G., et al. (2021). Characterisation of analogue front end and time walk in CMOS active pixel sensor. J. Instrum., 16(12), P12020–12pp.
Abstract: In this work we investigated a method to determine time walk in an active silicon pixel sensor prototype using Edge-TCT with infrared laser charge injection. Samples were investigated before and after neutron irradiation to 5 . 10(14) n(eq)/cm(2). Threshold, noise and calibration of the analogue front end were determined with external charge injection. A spatially sensitive measurement of collected charge and time walk was carried out with Edge-TCT, showing a uniform charge collection and output delay in pixel centre. On pixel edges charge sharing was observed due to finite beam width resulting in smaller signals and larger output delay. Time walk below 25 ns was observed for charge above 2000 e(-) at a threshold above the noise level. Time walk measurement with external charge injection yielded identical results.
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Renner, J. et al, Romo-Luque, C., Carrion, J. V., Diaz, J., Martinez, A., Querol, M., et al. (2022). Monte Carlo characterization of PETALO, a full-body liquid xenon-based PET detector. J. Instrum., 17(5), P05044–17pp.
Abstract: New detector approaches in Positron Emission Tomography imaging will play an important role in reducing costs, lowering administered radiation doses, and improving overall performance. PETALO employs liquid xenon as the active scintillating medium and UV-sensitive silicon photomultipliers for scintillation readout. The scintillation time in liquid xenon is fast enough to register time-of-flight information for each detected coincidence, and sufficient scintillation is produced with low enough fluctuations to obtain good energy resolution. The present simulation study examines a full-body-sized PETALO detector and evaluates its potential performance in PET image reconstruction.
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