arXiv subjects

Luca Pattavina

Publications and source records attributed to Luca Pattavina.

5 recordsLinked to original sources

arXiv2026

Cryogenic performance of Silicon Photo-Multipliers at LN$_2$ temperature and at 3 K in the RES-NOVA cryostat

Silicon Photo-Multipliers (SiPMs) are semiconductor-based photodetectors that offer performance comparable to that of traditional Photo-Multiplier Tubes (PMTs), while providing several advantages, including low operating voltage, immunity to magnetic fields, compact size, and mechanical robustness. These features have led to their widespread adoption in scintillator-based detectors for both fundamental and applied physics. In recent years, there has been a growing interest in the detection of scintillation light at cryogenic temperatures in low-temperature experiments based on bolometric detectors, such as RES-NOVA and CUPID, as well as in emerging quantum applications. In the RES-NOVA experiment, radiopure PbWO$_4$ crystals are used to detect supernova neutrinos. The scintillation of PbWO$_4$ can only be evaluated at cryogenic temperatures, as the scintillation light yield is negligible at room temperature. We present measurements of the performance at cryogenic temperatures of Hamamatsu S13360-1350CS SiPMs in terms of breakdown voltage and gain, at 77~K (in a liquid nitrogen bath) and at 3~K. The cooling down to 3~K has been carried out using a Proteox LX cryostat from Oxford Instruments.

physics.ins-det↗

arXiv2026

ST-GRU PredRNN-V2: A GRU-Based Reformulation of PredRNN-V2 for Video Prediction

Video prediction requires models to capture complex spatiotemporal dependencies and to retain relevant information over long sequences. PredRNN and its successor PredRNN-V2 address this challenge with spatiotemporal Long Short-Term Memory (ST-LSTM) units that maintain two separate memory states, at the cost of a relatively complex recurrent building block. In this work, we investigate whether the simpler gating of Gated Recurrent Units (GRUs) can be transferred to spatiotemporal predictive learning. To this end, we develop a spatiotemporal GRU (ST-GRU) unit as a GRU-based alternative to the ST-LSTM. The ST-GRU replaces the ST-LSTM's three gates per memory state with two GRU-style gates (update and reset), and merges the temporal memory state into the hidden state, which reduces the number of parameters by about 5%. We incorporate the ST-GRU into PredRNN-V2 and evaluate the resulting model on the Moving MNIST video prediction benchmark, following the original experimental protocol. Averaged over ten predicted frames, the ST-GRU-based PredRNN-V2 achieves an MSE of 55.1, an SSIM of 0.883, an LPIPS of 0.065 and a PSNR of 19.53dB. It does not surpass the original ST-LSTM-based PredRNN-V2 on MSE, SSIM or PSNR, but it achieves a lower LPIPS and performs on par with the earlier ST-LSTM-based PredRNN, while using a simpler recurrent cell. These results suggest that ST-GRUs are a promising building block for spatiotemporal predictive learning and motivate further work on their design and integration.

cs.CV↗

arXiv2026

Boids of a Feather Flock Together - Evolving Prey Behaviours Under Different Predator Attack Strategies

Flocking and schooling are thought to have evolved partly as defences against predation, but how prey should balance social and escape tendencies may depend on the predator's hunting strategy. We extend the predator-prey boids model of Ojo et al. (2023), itself based on Reynolds' boids, by combining six prey movement tendencies (alignment, cohesion, separation, dodge, repel and wiggle) into a single weighted acceleration update, and by reformulating wiggle as a sinusoidal manoeuvre. We then use an evolutionary strategy to optimise the six behaviour coefficients for collective prey survival against four predator hunting strategies: attack-centroid, attack-nearest, attack-random and attack-peripheral. Across five independent trials per strategy, coefficients converged within trials and mean fitness remained stable or increased, although trials often settled in different local optima. Prey survival was highest under attack-centroid and lowest under attack-nearest, in line with our hypotheses. Against attack-centroid, prey evolved individualistic predator avoidance with high escape coefficients, whereas against the other three strategies they largely kept their flock formation. Across all strategies, evolution favoured a low repel coefficient and relatively high dodge and wiggle coefficients. Our results suggest that optimal anti-predator behaviour depends on the interplay between escape tendencies and the predator's hunting strategy.

q-bio.PE↗

arXiv2022

Online triggers for supernova and pre-supernova neutrino detection with cryogenic detectors

Supernovae (SNe) are among the most energetic events in the universe still far from being fully understood. An early and prompt detection of neutrinos is a one-time opportunity for the realization of the first multi-messenger observation of these events. In this work, we present the prospects of detecting neutrinos produced before (pre-SN) and during a SN while running an advanced cryogenic detector. The recent advancements of the cryogenic detector technique and the discovery of coherent elastic neutrino-nucleus scattering offer a wealth of opportunities in neutrino detection. The combination of the excellent energy resolution of this experimental technique, with the high cross section of this detection channel and its equal sensitivity to all neutrino flavors enables the realization of highly sensitive cm-scale neutrino telescopes, as the newly proposed RES-NOVA experiment. We present a detailed study on the detection promptness of pre-SN and SN neutrino signals, with direct comparisons among different classes of test statistics. While the well-established Poisson test offers in general best performance under optimal conditions, the non-parametric Recursive Product of Spacing statistical test (RPS) is more robust and ideal for triggering astrophysical neutrino signals with no specific prior knowledge. Based on our statistical tests the RES-NOVA experiment is able to identify SN neutrino signals at a 15 kpc distance with 95% of success rate, and pre-SN signal as far as 480 pc with a pre-warn time of the order of 10 s. These results demonstrate the potential of RPS for the identification of neutrino signals and the physics reach of the RES-NOVA experiment.

astro-ph.IM↗

arXiv2020

RES-NOVA: A new neutrino observatory based on archaeological lead

We propose the RES-NOVA project which will hunt neutrinos from core-collapse supernovae (SN) via coherent elastic neutrino-nucleus scattering (CE$ν$NS) using an array of archaeological lead (Pb) based cryogenic detectors. The high CE$ν$NS cross-section on Pb and the ultra-high radiopurity of archaeological Pb enable the operation of a high statistics experiment equally sensitive to all neutrino flavors with reduced detector dimensions in comparison with existing Neutrino Observatories, and easy scalability to larger detector volumes. RES-NOVA is planned to operate according to three phases with increasing detector volumes: (60 cm)$^3$, (140 cm)$^3$, and ultimately 15$\times$(140 cm)$^3$. It will be sensitive to SN bursts up to Andromeda with 5$σ$ sensitivity with already existing technologies and will have excellent energy resolution with $1$ keV threshold. Within our Galaxy, it will be possible to discriminate core-collapse SNe from black hole forming collapses with no ambiguity even in the first phase of RES-NOVA. The average neutrino energy of all flavors, the SN neutrino light curve, and the total energy emitted in neutrinos can potentially be constrained with a precision of few $\%$ in the final detector phase. RES-NOVA will be sensitive to flavor-blind neutrinos from the diffuse SN neutrino background with an exposure of $620$ ton $\cdot$ y. The proposed RES-NOVA project has the potential to lay down the foundations for a new generation of neutrino telescopes, while relying on a very simple technological setup

astro-ph.HE↗