55 research outputs found
Characterization of the SIDDHARTA-2 Setup via the Kaonic Helium Measurement
No full textThe aim of the SIDDHARTA-2 experiment is to perform the first measurement ever of the width and shift induced by the strong interaction to the 2p -> 1s energy transition of kaonic deuterium. This ambitious goal implies a challenging task due to the very low X-ray yield of kaonic deuterium, which is why an accurate and thorough characterization of the experimental apparatus is mandatory before starting the data-taking campaign. Helium-4 is an excellent candidate for this characterization since it exhibits a high yield in particular for the 3d -> 2p transition, roughly 100 times greater than that of the kaonic deuterium. The ultimate goal of the work reported in this paper is to study the performances of the full experimental setup in view of the kaonic deuterium measurement. This is carried out by measuring the values of the shift and the width for the 3d -> 2p energy transition of kaonic helium-4, induced by the strong interaction. The values obtained for these quantities, for a total integrated luminosity of similar to 31/pb, are epsilon 2p=2.0 +/- 1.2(stat)+/- 1.5(syst)eV and Gamma 2p=1.9 +/- 5.7(stat)+/- 0.7(syst)eV. The results, compared to the value of the shift measured by the SIDDHARTA experiment epsilon 2p=0 +/- 6(stat)+/- 2(syst)eV, show a net enhancement of the resolution of the apparatus, providing strong evidence of the potential to perform the challenging measurement of the kaonic deuterium
Maio 4.0. Progettazione di spazi abitativi e ricettivi per ecoturismo mediante sistemi antisismici in CLT e timber frame
No full textLAUREA SPECIALISTICA A CICLO UNICOLa storia sismica della Penisola annovera un susseguirsi di eventi tellurici di differente intensità, causa di ingenti danni e crolli al fragile patrimonio edilizio diffuso sul territorio italiano, a cui sono seguiti differenti approcci alla ricostruzione nell’alternanza di soluzioni progettuali fallimentari e spesso non adeguate alle esigenze del contesto.
Il 21 agosto 2017 il cuore dell’isola d’Ischia è colpito da una scossa di terremoto con epicentro nel quartiere storico del Maio, nell’entroterra del comune di Casamicciola Terme. I crolli e le macerie di tale evento gravano tutt’oggi sulla vita comunitaria della popolazione sfollata. Ricostruire dov’era ma non com’era, riscoprendo nella risorsa naturale e sentieristica dell’isola verde una nuova identità per le comunità isolane e uno strumento di valorizzazione del turismo ischitano in chiave ecosostenibile.
Maio 4.0 nasce dalla necessità di coniugare ricostruzione e turismo non erosivo entro l’omonimo quartiere ischitano adottando un approccio metodologico mutuato dalla nascente Industria 4.0, ponendo a sistema le necessità fisico-funzionali dell’utente con un paradigma progettuale di natura digitale. La strategia progettuale intrapresa persegue il connubio tra il linguaggio architettonico vernacolare, le esigenze di resilienza strutturale imposte dal contesto fortemente sismico e i crescenti requisiti in termini di qualità dell’abitare.
L’esito della presente ricerca è un ecosistema ove coesistono ambienti residenziali per la popolazione sfollata e attività ricettive a servizio del progetto ecoturistico, caratterizzati da una comune espressione mediterranea, tramite l’alternarsi di spazi pubblici vegetali. Il sistema tecnologico-strutturale è basato sull’impiego di materiali di origine naturale, sia nella forma di un’innovativa struttura ibrida in legno -adottando simultaneamente tecnologie CLT, Timber Frame ed elementi prefabbricati- che nella composizione di un involucro atto a garantire elevate prestazioni in termini di comfort abitativo, efficienza energetica e minima impronta di carbonio.
Il nuovo quartiere del Maio dimostra come sia possibile, tramite un approccio progettuale olistico e integrato, affrontare il complesso ed eterogeneo tema della ricostruzione post-sismica.The seismic history of the Italian peninsula witnesses a high number of variously intense earthquakes, which have caused throughout the country extensive damage and collapse to the fragile building heritage. This has resulted in different approaches to reconstruction and in the alternation of unsuccessful design solutions that seldom met the needs of the context.
On 21 August 2017 the heart of the island of Ischia was hit by an earthquake with the historic district of Maio, in the inland of the municipality of Casamicciola Terme, as epicentral zone. The collapses and rubble from this event still burden on the displaced population’s social life. Rebuilding where it was rather than as it was, rediscovering natural resources and pathways of the green island as a new identity for the communities and a tool for enhancing Ischia's tourism in an eco-sustainable way.
Maio 4.0 stems from the need to combine reconstruction and non-erosive tourism within the island's namesake district, adopting a methodological approach borrowed from the emerging Industry 4.0 thus merging the physical and functional needs of users with a digital design paradigm. The undertaken design strategy pursues the union between vernacular architectural language, the need for structural resilience imposed by the highly seismic context and the growing requirements regarding quality of living.
The result of this research is an ecosystem where residential environments for the evacuee population and accommodation activities serving the ecotourism project coexist. Such spaces are characterised by a common Mediterranean expression and bond together through the alternation of public planted spaces. The technological-structural system is based on the use of nature-based materials. This takes place both in the form of an innovative hybrid timber structure, adopting simultaneously CLT technologies, Timber Frame and precast elements, and in the design of an envelope able to guarantee high performance in terms of living comfort, energy efficiency and minimum carbon footprint.
The new Maio district demonstrates how it is possible, through a holistic and integrated design approach, to tackle the complex and heterogeneous issue of post-seismic reconstruction
First Stability Characterization for a CZT Detection System in an e+e− Collider Environment
No full textThe SIDDHARTA-2 collaboration has developed a novel X-ray detection system based on cadmium-zinc-telluride (CZT, CdZnTe), marking the first application of this technology at the DAΦNE electron-positron collider at INFN-LNF. This work aims to demonstrate the stability of the detectors’ performance in terms of linearity and resolution over short and long periods, thereby establishing their suitability for precise spectroscopic measurements within a collider environment. A reference calibration spectrum is presented in association with findings from assessments of linearity and resolution stability. Additionally, this study introduces a validated model of the response function of the detector. The relative deviations from the nominal values for the source transitions, obtained by fitting the entire spectrum with a background function and the previously introduced response function, are reported. Finally, a comparison of the calibration performance with and without beams circulating in the collider’s rings is presented. These promising results pave the way for applying CZT detectors in kaonic atom studies and, more generally, in particle and nuclear physics spectroscopy
A Novel Approach to Parameter Determination of the Continuous Spontaneous Localization Collapse Model
No full textModels of dynamical wave function collapse consistently describe the breakdown of the quantum superposition with the growing mass of the system by introducing non-linear and stochastic modifications to the standard Schrödinger dynamics. Among them, Continuous Spontaneous Localization (CSL) was extensively investigated both theoretically and experimentally. Measurable consequences of the collapse phenomenon depend on different combinations of the phenomenological parameters of the model—the strength λ and the correlation length rC—and have led, so far, to the exclusion of regions of the admissible (λ−rC) parameters space. We developed a novel approach to disentangle the λ and rC probability density functions, which discloses a more profound statistical insight
Testing Pauli Exclusion Principle for electrons at the LNGS underground laboratory: The VIP-2 experiment
No full textThe VIP-2 experiment tests the Pauli Exclusion Principle (PEP) for electrons at the Gran Sasso underground National Laboratory (LNGS) of INFN in Italy, looking for a possible violation. The LNGS provide an extremely low background environment, ideal for performing high precision X-ray spectroscopy measurements on electrons atomic transitions.
The core of the VIP-2 experimental apparatus is based on a copper target circulated by a Direct Current (DC) and surrounded by silicon drift detectors (SDDs), which offer excellent performance in X-ray spectroscopy in the energy range experimentally observed by VIP-2. The aim of VIP-2 is to look for eventual PEP-forbidden K_α transitions (2p → 1s) in copper atoms, when the 1s level would be already occupied by two electrons, in contradiction with PEP. The energy of the K_α forbidden transitions is about 300 eV less than the nominal energy of the K_α PEP-allowed transition. This energy shift is due to the screening effect produced by the extra electron in fundamental level, and is detectable by means of a high precision X-ray spectroscopy measurement. About ten years ago, the VIP experiment set the best upper limit on the PEP violation probability β^2/2 < 4.7 × 10^−29 for electrons. The goal of the VIP-2 experiment is to improve this limit by two orders of magnitude. This paper presents a new preliminary result, obtained by analysing two sets of data collected with a partial configuration of the VIP-2 apparatus
Testing the Pauli Exclusion Principle across the Periodic Table with the VIP-3 Experiment
No full textThe Pauli exclusion principle (PEP), a cornerstone of quantum mechanics and whole science, states that in a system, two fermions can not simultaneously occupy the same quantum state. Several experimental tests have been performed to place increasingly stringent bounds on the validity of PEP. Among these, the series of VIP experiments, performed at the Gran Sasso Underground National Laboratory of INFN, is searching for PEP-violating atomic X-ray transitions in copper. In this paper, the upgraded VIP-3 setup is described, designed to extend these investigations to higher-Z elements such as zirconium, silver, palladium, and tin. We detail the enhanced design of this setup, including the implementation of cutting-edge, 1 mm thick, silicon drift detectors, which significantly improve the measurement sensitivity at higher energies. Additionally, we present calculations of expected PEP-violating energy shifts in the characteristic lines of these elements, performed using the multi-configurational Dirac–Fock method from first principles. The VIP-3 realization will contribute to ongoing research into PEP violation for different elements, offering new insights and directions for future studies
Analysis methods used and planned for VIP-2
No full textVIP-2 (VIolation of Pauli exclusion principle - 2) is an underground experiment sited in the underground “Laboratori Nazionali del Gran Sasso.” It aims to investigate possible violations of the Pauli Exclusion Principle (PEP) and, in this context, Quantum Gravity models implying violations of PEP. While an upper limit of PEP violation probability is recently published, the data requires further developments of accurate analysis techniques and methods. In this contribution, we present an overview of the methodologies proposed for current and planned analysis
VIP-2 with modulated current: pathfinder for enhanced Pauli exclusion principle violation studies
No full textFermions are subject to the Pauli Exclusion Principle (PEP), which is grounded on the spin-statistics theorem and, hence, related to the very same structure of the underlying symmetries. The VIP-2 (VIolation of Pauli exclusion principle - 2) experiment has been performing extreme sensitivity tests of the PEP, up to its current and final configuration, exploiting several experimental setups designed to study different theoretical models of PEP violation, looking for a faint signal of physics Beyond the Standard Model.A current is introduced in the copper target to bring new electrons into the system and, hence, fulfill the requirements of the Messiah-Greenberg Super-Selection rule. The searched spin-statistics violating signal corresponds to X-rays emitted when the new electrons perform atomic transitions to the already filled fundamental level of copper. This work analyzes the set of the VIP-2 data corresponding to a test run of 68 days in a current modulated regime alternating no current with current data-taking in short periods (50 s each), instead the usual alternating months-long data-taking of each of these two phases. We propose an analysis method to improve the experiment’s sensitivity: a spectral analysis constraint with the Discrete Fourier Transformation of the data. Compared to the spectrum-only analysis, about a factor of 1.5 of improvement to the limit for the probability of PEP violation for electrons was obtained
Testing the Pauli Exclusion Principle across the Periodic Table with the VIP-3 Experiment
No full textThe Pauli exclusion principle (PEP), a cornerstone of quantum mechanics and whole science, states that in a system, two fermions can not simultaneously occupy the same quantum state. Several experimental tests have been performed to place increasingly stringent bounds on the validity of PEP. Among these, the series of VIP experiments, performed at the Gran Sasso Underground National Laboratory of INFN, is searching for PEP-violating atomic X-ray transitions in copper. In this paper, the upgraded VIP-3 setup is described, designed to extend these investigations to higher-Z elements such as zirconium, silver, palladium, and tin. We detail the enhanced design of this setup, including the implementation of cutting-edge, 1 mm thick, silicon drift detectors, which significantly improve the measurement sensitivity at higher energies. Additionally, we present calculations of expected PEP-violating energy shifts in the characteristic lines of these elements, performed using the multi-configurational Dirac–Fock method from first principles. The VIP-3 realization will contribute to ongoing research into PEP violation for different elements, offering new insights and directions for future studies
Optimization of a BEGe Detector Setup for Testing Quantum Foundations in the Underground LNGS Laboratory
No full textIn this work, we report on tests performed with an experimental apparatus prototype based on a broad-energy germanium detector aimed at investigating topical, foundational issues in quantum mechanics: i.e., possible violations of the spin-statistics connection and models of dynamical wave function collapse. Our recent phenomenological analyses demonstrated the importance of pushing the research of new physics signal, predicted in these fields, to an energy range below 10 keV. We describe the development of the dedicated data acquisition system and of the pulse shape discrimination algorithm, which have already allowed us to get a factor two improvement in the lower energy threshold. Future plans are discussed to further improve the lower energy threshold to the level of a few keV
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