Optimum Filter Synthesis with DPLMS Method for Energy Reconstruction

Optimum filters are granted increasing recognition as valuable tools for parametric estimation in many scientific and technical fields. The DPLMS method, introduced some twenty years ago, is effective among the synthesis algorithms since it derives the optimum filters directly from the experimental signal and noise waveforms. Two new extensions of the DPLMS method are here presented. The first one speeds up the synthesis phase and improves the energy estimation by synthesizing optimum filters with automatically designed flat-top length. The second one improves the quality of parameter estimation in multi-channel systems by taking advantage of the inter-channel noise correlation properties. The theoretical and functional aspects behind the DPLMS method for optimum filter synthesis are first recalled and illustrated in more detail. The two new DPLMS extensions are subsequently introduced from the theoretical viewpoint and more thoroughly considered from the applicative perspective. The DPLMS optimum filters have been applied first to simulated signals with various amounts and characteristics of superimposed noise and then to the experimental waveforms acquired from a solid-state Ge detector. The results obtained are considered from both the absolute viewpoint and in comparison with those of more traditional, suboptimal filters. The results demonstrate the effectiveness of the two new DPLMS extensions. For single-channel energy estimations, the optimum filters provide comparatively better results than the other filters. The DPLMS multi-channel optimum filters further enhance the quality of the estimations, compared to single-channel optimum filters, with non-negligible inter-channel noise correlation. The effectiveness and robustness of the DPLMS method in synthesizing high-quality filters for energy estimation will be tested soon within leading-edge multi-channel physics experiments.Comment: 15 pages, 13 figure

The Front-End electronics for the liquid Argon instrumentation of the LEGEND-200 experiment

In this paper we provide a detailed technical description of the Front-End electronics for the liquid Argon instrumentation of the LEGEND-200 experiment, searching for the very rare, hypothetical neutrinoless double $\beta$ decay process at the Italian Laboratori Nazionali del Gran Sasso. The design stems from the need to read out the silicon photo-multiplier response to the scintillation light in the liquid Argon with excellent single-photon resolution. The Front End is required to be placed far from the detectors to meet the experiment's radio-purity constraints, which represented a challenge for a high signal-to-noise ratio. We address how this could be achieved in a stable way. The system was installed in July 2021 and has been commissioned with the rest of LEGEND-200, proving we could attain a very low overall level of electrical noise, of 200 $\mu$V on average

LEGEND-1000 Preconceptual Design Report

We propose the construction of LEGEND-1000, the ton-scale Large Enriched Germanium Experiment for Neutrinoless $\beta \beta$ Decay. This international experiment is designed to answer one of the highest priority questions in fundamental physics. It consists of 1000 kg of Ge detectors enriched to more than 90% in the $^{76}$Ge isotope operated in a liquid argon active shield at a deep underground laboratory. By combining the lowest background levels with the best energy resolution in the field, LEGEND-1000 will perform a quasi-background-free search and can make an unambiguous discovery of neutrinoless double-beta decay with just a handful of counts at the decay $Q$ value. The experiment is designed to probe this decay with a 99.7%-CL discovery sensitivity in the $^{76}$Ge half-life of $1.3\times10^{28}$ years, corresponding to an effective Majorana mass upper limit in the range of 9-21 meV, to cover the inverted-ordering neutrino mass scale with 10 yr of live time

GERDA final results on neutrinoless double beta decay search

The GErmanium Detector Array (Gerda) experiment searched at Laboratori Nazionali del Gran Sasso of INFN for neutrinoless double beta (0νββ) decay of the 76Ge isotope. The experiment has used 44 kg of bare high-purity germanium detectors, acting simultaneously as source and detector, deployed into ultra-pure liquid argon. The last Gerda results lead the 0νββ decay field, reporting the highest sensitivity on the half-life of 0νββ decay, 1.8×1026 yr, and the lowest background index at the Q-value of the decay, of 5.2×10−4 cts/(keV·kg·yr). These achievements are the result of the careful selection of highly radiopure materials and of efficient background suppression techniques. The experimental setup, the active background reduction techniques and the final results of Gerda will be summarized

Searching for neutrinoless double beta decay with LEGEND-200 experiment

Experiments searching for neutrinoless double beta (0νββ) decay, have the capability to unveil the neutrinos mysteries: defining their absolute scale mass and establishing their nature (Dirac or Majorana particles). The LEGEND collaboration works to develop the largest 76Ge 0νββ decay experiment in history. The collaboration was born from the synergy of two collaborations, Gerda and Majorana, and additional institutes. The first phase of the experiment, called LEGEND-200, is under construction at LNGS of INFN: the experiment aims to reach a sensitivity on the half-life of 0νββ decay up to 1027 yr by operating about 200 kg of HPGe detectors within the upgraded Gerda infrastructure. The experimental setup and the LAr veto system used to actively suppress background events, will be summarized

Neutrinoless Double Beta Decay

This White Paper, prepared for the Fundamental Symmetries, Neutrons, and Neutrinos Town Meeting related to the 2023 Nuclear Physics Long Range Plan, makes the case for double beta decay as a critical component of the future nuclear physics program. The major experimental collaborations and many theorists have endorsed this white paper

Neutrinoless Double Beta Decay

This White Paper, prepared for the Fundamental Symmetries, Neutrons, and Neutrinos Town Meeting related to the 2023 Nuclear Physics Long Range Plan, makes the case for double beta decay as a critical component of the future nuclear physics program. The major experimental collaborations and many theorists have endorsed this white paper

Neutrinoless Double Beta Decay

International audienceThis White Paper, prepared for the Fundamental Symmetries, Neutrons, and Neutrinos Town Meeting related to the 2023 Nuclear Physics Long Range Plan, makes the case for double beta decay as a critical component of the future nuclear physics program. The major experimental collaborations and many theorists have endorsed this white paper