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Marzio De Napoli

Publications and source records attributed to Marzio De Napoli.

7 recordsLinked to original sources
arXiv2026

Exploiting the latent space of deep AutoEncoders for the identification of signal pulses in noisy time-series

We propose a data-driven procedure, based on convolutional variational autoencoders, to identify the presence of signal pulses in long time-series. The dataset consists of synthetic waveforms, each composed of non-gaussian noise and a log-normal shaped signal of variable intensity, with a length of 10,000 samples. The model heavily compresses the input waveforms, allowing a direct study of such a reduced representation. After training for 150 epochs on 7,500 waveforms, a region in the latent space where the network encodes time-series presenting only background noise emerges, allowing in turn to tag as candidates for containing a signal those falling outside. When applied on a test dataset of freshly generated waveforms, 100% of the events with a large pulses are correctly labelled, and this fraction only decreases for signal amplitudes comparable with accidental noise pulses. This approach was designed to fully exploit the measurements in dual-phase Liquid Argon Time Projection Chambers, as the one of the Recoil Directionality experiment, built in the context of the Darkside project.

physics.ins-det↗
arXiv2026

The Darkside-20k Data Acquisition System

DarkSide-20k is a WIMP search experiment using liquid argon as a target, designed to perform a background-free search for dark matter with unprecedented sensitivity, and is currently under construction at INFN Laboratori Nazionali del Gran Sasso, Italy. The detector comprises a dual-phase Time Projection Chamber complemented with external veto systems and is equipped with a total of 2720 SiPM-based readout channels. This work presents the DAQ system designed for DarkSide-20k. The system is capable of continuous, triggerless digitisation of the waveforms with high single-photoelectron detection efficiency and online processing, ensuring data reduction for long-term storage. The DarkSide-20k DAQ system employs commercial CAEN VX2745 digitisers with custom FPGA firmware implementation. Timing and synchronisation across all 48 digitisers are provided by custom Global and Crate Data Manager boards distributing a phase-aligned clock derived from a disciplined rubidium standard. Waveform segments are processed in real time by Front End Processor machines. Data are organised into collections containing whole detector information and distributed across a farm of Time Slice Processors for event reconstruction, classification, and further reduction before storage and offline analysis. A full "Quadrant" of the system, corresponding to one quarter of the final DAQ, has been assembled and validated at TRIUMF laboratory in Canada. The Quadrant has been stress-tested with simultaneous pulses and demonstrated sustained digitizer readout exceeding expected physics rates and stable long-term performance.

physics.ins-det↗
arXiv2022

The Heavy Photon Search Experiment

The Heavy Photon Search (HPS) experiment is designed to search for a new vector boson $A^\prime$ in the mass range of 20 MeV/$c^2$ to 220 MeV/$c^2$ that kinetically mixes with the Standard Model photon with couplings $ε^2 >10^{-10}$. In addition to the general importance of exploring light, weakly coupled physics that is difficult to probe with high-energy colliders, a prime motivation for this search is the possibility that sub-GeV thermal relics constitute dark matter, a scenario that requires a new comparably light mediator, where models with a hidden $U(1)$ gauge symmetry, a "dark", "hidden sector", or "heavy" photon, are particularly attractive. HPS searches for visible signatures of these heavy photons, taking advantage of their small coupling to electric charge to produce them via a process analogous to bremsstrahlung in a fixed target and detect their subsequent decay to $\mathrm{e}^+ \mathrm{e}^-$ pairs in a compact spectrometer. In addition to searching for $\mathrm{e}^+ \mathrm{e}^-$ resonances atop large QED backgrounds, HPS has the ability to precisely measure decay lengths, resulting in unique sensitivity to dark photons, as well as other long-lived new physics. After completion of the experiment and operation of engineering runs in 2015 and 2016 at the JLab CEBAF, physics runs in 2019 and 2021 have provided datasets that are now being analyzed to search for dark photons and other new phenomena.

hep-ex↗
arXiv2020

Searching in the dark: the hunt for the dark photon

The existence of Dark Matter (DM) is a well established fact since many decades, thanks to the observation of the effects of its gravitational interaction with the ordinary matter in the Universe. However, our knowledge of the Dark Matter features is still rather scarce. Indeed, one of the biggest quests in fundamental science today is the investigation of Dark Matter nature, from its origin to its composition, and the way its constituents interact with the ordinary matter, apart from gravity. Huge and ambitious efforts have been spent in the last years into its identification, concentrating especially on the search of viable Weakly Interacting Massive Particle candidates. However, no positive results have been achieved so far along this direction. On the other hand, many fascinating new ideas and models for its interpretation have been blooming: among them, an intriguing hypothesis is that the Dark Matter constituents could be neutral under Standard Model interactions, but they could interact through a new, still unknown, force under a "hidden" charge. This new hidden symmetry would be mediated by a massive gauge boson, the dark photon, which is expected to couple to the Standard Model via a kinetic mixing. The search for such a massive mediator has been pursued with large enthusiasm and dedication in the latest years, as its observation could be within the reach of many already existing experimental facilities, both based on accelerators

hep-ph↗
arXiv2017

The HPS electromagnetic calorimeter

The Heavy Photon Search experiment (HPS) is searching for a new gauge boson, the so-called "heavy photon." Through its kinetic mixing with the Standard Model photon, this particle could decay into an electron-positron pair. It would then be detectable as a narrow peak in the invariant mass spectrum of such pairs, or, depending on its lifetime, by a decay downstream of the production target. The HPS experiment is installed in Hall-B of Jefferson Lab. This article presents the design and performance of one of the two detectors of the experiment, the electromagnetic calorimeter, during the runs performed in 2015-2016. The calorimeter's main purpose is to provide a fast trigger and reduce the copious background from electromagnetic processes through matching with a tracking detector. The detector is a homogeneous calorimeter, made of 442 lead-tungstate (PbWO4) scintillating crystals, each read out by an avalanche photodiode coupled to a custom trans-impedance amplifier.

physics.ins-det↗
arXiv2016

Dark Sectors 2016 Workshop: Community Report

This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years.

hep-ph↗