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Search Results: 1 - 10 of 461778 matches for " A. Nucciotti "
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Double beta decay: experiments and theory review
A. Nucciotti
Physics , 2007,
Abstract: Neutrinoless double beta decay is one of the most powerful tools to set the neutrino mass absolute scale and establish whether the neutrino is a Majorana particle. After a summary of the neutrinoless double beta decay phenomenology, the present status of the experimental search for this rare decay is reported and the prospects for next generation experiments are reviewed.
Statistical sensitivity of 163-Ho electron capture neutrino mass experiments
A. Nucciotti
Physics , 2014, DOI: 10.1140/epjc/s10052-014-3161-3
Abstract: Large calorimetric neutrino mass experiments using thermal detectors are possibly going to play a crucial role in the challenge for assessing the neutrino mass. This paper describe a tool based on Monte Carlo methods which has been developed to estimate the statistical sensitivity of calorimetric neutrino mass experiments using the 163-Ho electron capture decay. The tool is applied to investigate the effect of various experimental parameters and the results useful for designing an experiment with sub-eV sensitivity are given.
Neutrino mass calorimetric searches in the MARE experiment
A. Nucciotti,for the MARE Collaboration
Physics , 2010,
Abstract: The international project ``Microcalorimeter Arrays for a Rhenium Experiment'' (MARE) aims at the direct and calorimetric measurement of the electron neutrino mass with sub-electronvolt sensitivity. Calorimetric neutrino mass experiments measure all the energy released in a beta decay except for the energy carried away by the neutrino, therefore removing the most severe systematic uncertainties which have plagued the traditional and, so far, more sensitive spectrometers. Calorimetric measurements are best realized exploiting the thermal detection technique. This approach uses thermal microcalorimeters whose absorbers contain a low transition energy Q beta decaying isotope. To date the two best options are 187Re and 163Ho. While the first beta decays, the latter decays via electron capture, but both have a Q value around 2.5 keV. The potential of using 187Re for a calorimetric neutrino mass experiment has been already demonstrated. On the contrary, no calorimetric spectrum of 163Ho has been so far measured with the precision required to set a useful limit on the neutrino mass. In this talk we present the status and the perspectives of the MARE project activities for the active isotope selection and the single channel development. We also discuss the neutrino mass statistical sensitivity achievable with both isotopes.
The use of low temperature detectors for direct measurements of the mass of the electron neutrino
Angelo Nucciotti
Physics , 2015,
Abstract: Recent years have witnessed many exciting breakthroughs in neutrino physics. The detection of neutrino oscillations has proved that neutrinos are massive particles but the assessment of their absolute mass scale is still an outstanding challenge in today particle physics and cosmology. Since low temperature detectors were first proposed for neutrino physics experiments in 1984, there have been tremendous technical progresses: today this technique offers the high energy resolution and scalability required to perform competitive experiments challenging the lowest electron neutrino masses. This paper reviews the thirty-year effort aimed at realizing a calorimetric measurements with sub-eV neutrino mass sensitivity using low temperature detectors.
Investigation of peak shapes in the MIBETA experiment calibrations
E. Ferri,S. Kraft-Bermuth,A. Monfardini,A. Nucciotti,D. Schaeffer,M. Sisti
Physics , 2012, DOI: 10.1140/epja/i2012-12131-5
Abstract: In calorimetric neutrino mass experiments, where the shape of a beta decay spectrum has to be precisely measured, the understanding of the detector response function is a fundamental issue. In the MIBETA neutrino mass experiment, the X-ray lines measured with external sources did not have Gaussian shapes, but exhibited a pronounced shoulder towards lower energies. If this shoulder were a general feature of the detector response function, it would distort the beta decay spectrum and thus mimic a non-zero neutrino mass. An investigation was performed to understand the origin of the shoulder and its potential influence on the beta spectrum. First, the peaks were fitted with an analytic function in order to determine quantitatively the amount of events contributing to the shoulder, also depending on the energy of the calibration X-rays. In a second step, Montecarlo simulations were performed to reproduce the experimental spectrum and to understand the origin of its shape. We conclude that at least part of the observed shoulder can be attributed to a surface effect.
Archeologia dell’edilizia storica e costruzione del documento archeologico. Problemi di popolamento mediterraneo. II. Organizzazione del cantiere di una fortezza rurale di XIII secolo: il cassero di Montelaterone (Monte Amiata - Toscana)
Nucciotti, Michele,Leporatti, Silvia
Arqueología de la Arquitectura , 2003,
Abstract: This paper aims to show the organization of the stonework in the fortress of Montelaterone (Amiata, Tuscany), by comparing documental and archaeological sources. The building analysed is found in a historical sub-region, Mount Amiata, which from the 11th to the 14th century was progressively under the control of a great imperial abbey (San Asalvatore di Monte Amiata) of one of the principal aristocratic Tuscan families, the Aldobrandeschi, until control passed to Siena in the 14th century. The University of Florence since 1997 has been involved in an archaeological project aimed at studying how power was structured by the leading local groups and their architectonic policy. This paper presents the results of the study of the castle at Montelaterone. Its construction, carried out in Siena in the 1260s, represented a profound transformation in the organization of architectonic activity and of existing relationships between the local community and the lords of the abbey of San Salvatore in favour of the former. No disponible.
Algorithms for Identification of Nearly-Coincident Events in Calorimetric Sensors
B. Alpert,E. Ferri,D. Bennett,M. Faverzani,J. Fowler,A. Giachero,J. Hays-Wehle,M. Maino,A. Nucciotti,A. Puiu,D. Swetz,J. Ullom
Physics , 2015,
Abstract: For experiments with high arrival rates, reliable identification of nearly-coincident events can be crucial. For calorimetric measurements to directly measure the neutrino mass such as HOLMES, unidentified pulse pile-ups are expected to be a leading source of experimental error. Although Wiener filtering can be used to recognize pile-up, it suffers errors due to pulse-shape variation from detector nonlinearity, readout dependence on sub-sample arrival times, and stability issues from the ill-posed deconvolution problem of recovering Dirac delta-functions from smooth data. Due to these factors, we have developed a processing method that exploits singular value decomposition to (1) separate single-pulse records from piled-up records in training data and (2) construct a model of single-pulse records that accounts for varying pulse shape with amplitude, arrival time, and baseline level, suitable for detecting nearly-coincident events. We show that the resulting processing advances can reduce the required performance specifications of the detectors and readout system or, equivalently, enable larger sensor arrays and better constraints on the neutrino mass.
Development of microwave superconducting microresonators for neutrino mass measurement in the HOLMES framework
A. Giachero,P. K. Day,P. Falferi,M. Faverzani,E. Ferri,C. Giordano,M. Maino,B. Margesin,R. Mezzena,R. Nizzolo,A. Nucciotti,A. Puiu,L. Zanetti
Physics , 2015,
Abstract: The European Research Council has recently funded HOLMES, a project with the aim of performing a calorimetric measurement of the electron neutrino mass measuring the energy released in the electron capture decay of \textsuperscript{163}Ho. The baseline for HOLMES are microcalorimeters coupled to Transition Edge Sensors (TESs) read out with rf-SQUIDs, for microwave multiplexing purposes. A promising alternative solution is based on superconducting microwave resonators, that have undergone rapid development in the last decade. These detectors, called MKIDs (Microwave Kinetic Inductance Detectors), are inherently multiplexed in the frequency domain and suitable for even larger-scale pixel arrays, with theoretical high energy resolution and fast response. The aim of our activity is to develop arrays of microresonator detectors for X-ray spectroscopy and suitable for the calorimetric measurement of the energy spectra of \textsuperscript{163}Ho. Superconductive multilayer films composed by a sequence of pure Titanium and stoichiometric TiN layers show many ideal properties for MKIDs, such as low loss, large sheet resistance, large kinetic inductance, and tunable critical temperature $T_c$. We developed Ti/TiN multilayer microresonators with $T_c$ within the range from 70\,mK to 4.5\,K and with good uniformity. In this contribution we present the design solutions adopted, the fabrication processes and the characterization results.
The low-temperature energy calibration system for the CUORE bolometer array
S. Sangiorgio,L. M. Ejzak,K. M. Heeger,R. H. Maruyama,A. Nucciotti,M. Olcese,T. S. Wise,A. L. Woodcraft
Physics , 2009, DOI: 10.1063/1.3292432
Abstract: The CUORE experiment will search for neutrinoless double beta decay (0nDBD) of 130Te using an array of 988 TeO_2 bolometers operated at 10 mK in the Laboratori Nazionali del Gran Sasso (Italy). The detector is housed in a large cryogen-free cryostat cooled by pulse tubes and a high-power dilution refrigerator. The TeO_2 bolometers measure the event energies, and a precise and reliable energy calibration is critical for the successful identification of candidate 0nDBD and background events. The detector calibration system under development is based on the insertion of 12 gamma-sources that are able to move under their own weight through a set of guide tubes that route them from deployment boxes on the 300K flange down into position in the detector region inside the cryostat. The CUORE experiment poses stringent requirements on the maximum heat load on the cryostat, material radiopurity, contamination risk and the ability to fully retract the sources during normal data taking. Together with the integration into a unique cryostat, this requires careful design and unconventional solutions. We present the design, challenges, and expected performance of this low-temperature energy calibration system.
Critical Temperature tuning of Ti/TiN multilayer films suitable for low temperature detectors
A. Giachero,P. Day,P. Falferi,M. Faverzani,E. Ferri,C. Giordano,B. Marghesin,F. Mattedi,R. Mezzena,R. Nizzolo,A. Nucciotti
Physics , 2013, DOI: 10.1007/s10909-013-1078-0
Abstract: We present our current progress on the design and test of Ti/TiN Multilayer for use in Kinetic Inductance Detectors (KIDs). Sensors based on sub-stoichiometric TiN film are commonly used in several applications. However, it is difficult to control the targeted critical temperature $T_C$, to maintain precise control of the nitrogen incorporation process and to obtain a production uniformity. To avoid these problems we investigated multilayer Ti/TiN films that show a high uniformity coupled with high quality factor, kinetic inductance and inertness of TiN. These features are ideal to realize superconductive microresonator detectors for astronomical instruments application but also for the field of neutrino physics. Using pure Ti and stoichiometric TiN, we developed and tested different multilayer configuration, in term of number of Ti/TiN layers and in term of different interlayer thicknesses. The target was to reach a critical temperature $T_C$ around $(1\div 1.5)$ K in order to have a low energy gap and slower recombination time (i.e. low generation-recombination noise). The results prove that the superconductive transition can be tuned in the $(0.5\div 4.6)$ K temperature range properly choosing the Ti thickness in the $(0\div 15)$ nm range, and the TiN thickness in the $(5\div 100)$ nm range
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