57 research outputs found

    Search for neutrinoless double beta decay of 64 Zn and 70 Zn with CUPID-0

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    CUPID-0 is the first pilot experiment of CUPID, a next-generation project searching for neutrinoless double beta decay. In its first scientific run, CUPID-0 operated 26 ZnSe cryogenic calorimeters coupled to light detectors in the underground Laboratori Nazionali del Gran Sasso. In this work, we analyzed a ZnSe exposure of 11.34 kg year to search for the neutrinoless double beta decay of 70Zn and for the neutrinoless positron-emitting electron capture of 64Zn. We found no evidence for these decays and set 90% credible interval limits of T0ÎœÎČÎČ1/2(70Zn) > 1.6 1021 year and T0ÎœECÎČ+1/2(64Zn) > 1.2×1022 year, surpassing by more than one order of magnitude the previous experimental results (Belli et al. in J Phys G 38(11):115107, https://doi.org/10.1088/0954-3899/38/11/115107, 2011)

    Background model of the CUPID-0 experiment

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    CUPID-0 is the first large mass array of enriched Zn82Se scintillating low temperature calorimeters, operated at LNGS since 2017. During its first scientific runs, CUPID-0 collected an exposure of 9.95kgyear. Thanks to the excellent rejection of alpha particles, we attained the lowest background ever measured with thermal detectors in the energy region where we search for the signature of 82Se neutrinoless double beta decay. In this work we develop a model to reconstruct the CUPID-0 background over the whole energy range of experimental data. We identify the background sources exploiting their distinctive signatures and we assess their extremely low contribution [down to similar to 10-4 counts/(keVkgyear)] in the region of interest for 82Se neutrinoless double beta decay search. This result represents a crucial step towards the comprehension of the background in experiments based on scintillating calorimeters and in next generation projects such as CUPID

    Search of the neutrino-less double beta decay of 82 Se into the excited states of 82 Kr with CUPID-0

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    The CUPID-0 experiment searches for double beta decay using cryogenic calorimeters with double (heat and light) read-out. The detector, consisting of 24 ZnSe crystals 95% enriched in 82Se and two natural ZnSe crystals, started data-taking in 2017 at Laboratori Nazionali del Gran Sasso. We present the search for the neutrino-less double beta decay of 82Se into the 0+1, 2+1 and 2+2 excited states of 82Kr with an exposure of 5.74 kg·yr (2.24×1025 emitters·yr). We found no evidence of the decays and set the most stringent limits on the widths of these processes: G(82Se Âż82Kr0+1)8.55×10-24 yr-1, G (82 Se Âż82 Kr 2+1)<6.25×10-24 yr-1, G(82Se Âż82Kr2+2)8.25×10-24 yr-1 (90% credible interval)

    Perspectives of lowering CUORE thresholds with Optimum Trigger

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    CUORE is a cryogenic experiment that focuses on the search of neutrinoless double beta decay in 130Te and it is located at the Gran Sasso National Laboratories. Its detector consists of 988 TeO2 crystals operating at a base temperature of ~10 mK. It is the first ton-scale bolometric experiment ever realized for this purpose. Thanks to its large target mass and ultra-low background, the CUORE detector is also suitable for the search of other rare phenomena. In particular the low energy part of the spectra is interesting for the detection of WIMP-nuclei scattering reactions. One of the most important requirements to perform these studies is represented by the achievement of a stable energy threshold lower than 10 keV. Here, the CUORE capability to accomplish this purpose using a low energy software trigger will be presented and described

    Volume I. Introduction to DUNE

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    The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. This TDR is intended to justify the technical choices for the far detector that flow down from the high-level physics goals through requirements at all levels of the Project. Volume I contains an executive summary that introduces the DUNE science program, the far detector and the strategy for its modular designs, and the organization and management of the Project. The remainder of Volume I provides more detail on the science program that drives the choice of detector technologies and on the technologies themselves. It also introduces the designs for the DUNE near detector and the DUNE computing model, for which DUNE is planning design reports. Volume II of this TDR describes DUNE\u27s physics program in detail. Volume III describes the technical coordination required for the far detector design, construction, installation, and integration, and its organizational structure. Volume IV describes the single-phase far detector technology. A planned Volume V will describe the dual-phase technology

    Deep Underground Neutrino Experiment (DUNE), far detector technical design report, volume III: DUNE far detector technical coordination

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    The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. Volume III of this TDR describes how the activities required to design, construct, fabricate, install, and commission the DUNE far detector modules are organized and managed. This volume details the organizational structures that will carry out and/or oversee the planned far detector activities safely, successfully, on time, and on budget. It presents overviews of the facilities, supporting infrastructure, and detectors for context, and it outlines the project-related functions and methodologies used by the DUNE technical coordination organization, focusing on the areas of integration engineering, technical reviews, quality assurance and control, and safety oversight. Because of its more advanced stage of development, functional examples presented in this volume focus primarily on the single-phase (SP) detector module

    Highly-parallelized simulation of a pixelated LArTPC on a GPU

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    The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

    Lifestyle changes for the treatment of nonalcoholic fatty liver disease-a 2015-19 update

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    Background: Lifestyle interventions aimed at weight loss have been associated with improved liver enzymes, reduced intrahepatic triglyceride content, and improved histology (including reduced fibrosis stage). Objective: To revise the evidence on the beneficial effects of lifestyle changes accumulated since 2015, following the publication of the pivotal Cuban experience with histologic outcome. Methods: A PubMed search covering the period 2015 to July 2019 was carried out. All retrieved references were analyzed and double-checked by authors. Results: 20 new studies were identified; in addition, two relevant studies provided new evidence. Thirteen studies were classified as randomized, controlled studies, three as proof-of-concept/pilot studies, four as cohort observational studies. In an attempt to maintain a closer contact between participants and the treatment center, a study implemented regular phone calls, another an e-mail service, a third was based on text messages, and finally, a study was totally web-based. Notably, the web-based treatment, accessed following intense motivational inter-viewing, was not less effective than a standard group-based behavior program. Conclusion: Lifestyle changes should form the basis of any NAFLD intervention. Information technology provides the opportunity to expand treatment, bypassing job and time constraints in younger patients, and to maintain long-term contact between patients and therapists in the NAFLD population

    Detection of low energy antiproton annihilations in a segmented silicon detector

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    The goal of the AEbar gIS experiment at the Antiproton Decelerator (AD) at CERN, is to measure directly the Earth's gravitational acceleration on antimatter by measuring the free fall of a pulsed, cold antihydrogen beam. The final position of the falling antihydrogen will be detected by a position sensitive detector. This detector will consist of an active silicon part, where the annihilations take place, followed by an emulsion part. Together, they allow to achieve 1% precision on the measurement of bar g with about 600 reconstructed and time tagged annihilations. We present here the prospects for the development of the AEbar gIS silicon position sentive detector and the results from the first beam tests on a monolithic silicon pixel sensor, along with a comparison to Monte Carlo simulations

    Particle tracking at 4K: The Fast Annihilation Cryogenic Tracking (FACT) detector for the AEgIS antimatter gravity experiment

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    The AEgIS experiment is an international collaboration with the main goal of performing the fi rst direct measurement of the Earth ' s gravitational acceleration on antimatter. Critical to the success of AEgIS is the production of cold antihydrogen ( H) atoms. The FACT detector is used to measure the production and temperature of the H atoms and for establishing the formation of a H beam. The operating requirements for this detector are very challenging: it must be able to identify each of the thousand or so annihilations in the 1 ms period of pulsed H production, operate at 4 K inside a 1 T solenoidal fi eld and not produce more than 10 W of heat. The FACT detector consists of two concentric cylindrical layers of 400 scintillator fi bres with a 1 mm diameter and a 0.6 mm pitch. The scintillating fi bres are coupled to clear fi bres which transport the scintillation light to 800 silicon photomultipliers. Each silicon photomultiplier signal is connected to a linear ampli fi er and a fast discriminator, the outputs of which are sampled continuously by Field Programmable Gate Arrays (FPGAs). In the course of the developments for the FACT detector we have established the performance of scintillating fi bres at 4 K by means of a cosmic-ray tracker operating in a liquid helium cryostat. The FACT detector was installed in the AEgIS apparatus in December 2012 and will be used to study the H formation when the low energy antiproton physics programs resume at CERN in the Summer of 2014. This paper presents the design requirements and construction methods of the FACT detector and provides the fi rst results of the detector commissionin
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