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The interdisciplinarity of Special Relativity: A historical analysis
No full textThis paper is framed within the Erasmus+ project titled IDENTITIES, whose aim is to develop interdisciplinary teaching materials for pre-service teacher education. In collaboration with the research group in STEM education
of Crete, a blended module on special relativity has been developed. The module is based on an analysis of the original texts by Lorentz, Poincar´e, Einstein and Minkowski (written between 1904 and 1908), aimed to recognise the interplay between mathematics and physics implemented in the four papers. The analysis has been carried out by applying the “Boundary Crossing and Boundary Object” research framework developed in 2011 by Akkerman and Bakker. The results of the analysis show that Lorentz Transformations can be read as a Boundary Object and this lens allows for different nuances of the interplay between mathematics and
physics to be recognised in the four papers. A series of activities to be conducted in blended mode in a pre-service teacher education course have been designed with the goal of exploiting special relativity as a context to develop interdisciplinary skills
AstroGarden of Roma Tre University: From presence to online tour
No full textThe transition of teaching activities to online mode, forced by the Covid-19 emergency, had also positive aspects, as it pushed to create new contents and use new approaches. An example is represented by our experience at the Department of Mathematics and Physics of Roma Tre University, where we had to revolutionize an activity we carried on countless times over the years: the guided visit to our astronomical garden, the AstroGarden. In this paper, we analyze the new approach we used especially regarding the activities with the so-called oriented globe, the different audiences we reached and the positive feedback we received
The Pauli Exclusion Principle for electrons tested by VIP-2 at the LNGS laboratories
No full textThe VIP-2 experiment tests the Pauli Exclusion Principle (PEP) in a copper target circulated by a Direct Current, hunting for atomic Kα transitions (2p → 1s) that violate the PEP. Silicon Drift Detectors (SDDs) are installed around the
target to measure the atomic transitions with high-precision x-ray detectors. A PEPviolating Kα transition would occur if an electron arrived on the 1s orbital which is already occupied by two electrons. The energy of the Kα forbidden transition in copper is expected to be shifted down by about 300 eV with respect to the nominal energy of the Kα PEP-allowed transition (∼8 keV). The SDD resolution is 190 eV
(FWHM) at 8 keV and allows measuring and disentangling possible PEP-violating Kα transitions in copper. The VIP experiment sets an upper limit on the Pauli exclusion principle violation probability equal to β2/2 < 4.7×10−29 for electrons in copper. The VIP-2 experiment, presently in data taken at the National Laboratories of Gran Sasso (LNGS) in Italy, aims at improving the VIP limit by two orders of
magnitude. This paper will present a new preliminary upper limit obtained by analyzing two sets of data collected in a preliminary run with the VIP-2 apparatus
Decay studies in the A ∼ 225 Po-Fr region from the DESPEC campaign at GSI in 2021
No full textThe HISPEC-DESPEC collaboration aims at investigating the structure of exotic nuclei formed in fragmentation reactions with decay spectroscopy measurements, as part of the FAIR Phase-0 campaign at GSI. This paper reports on first results of an experiment performed in spring 2021, with a focus on β-decay studies in the Po-Fr nuclei in the 220 <A< 230 island of octupole deformation exploiting the DESPEC setup. Ion-beta correlations and fast-timing techniques are being employed, giving an insight into this difficult-to-reach region
Measurement of the cosmic-ray electron and positron spectrum with the Calorimetric Electron Telescope on the International Space Station
No full textThe CALorimetric Electron Telescope (CALET), operating onboard the International Space Station (ISS) since October 2015, is an experiment dedicated to high-energy astroparticle physics. The primary scientific goal of the CALET mission is to perform a high-precision measurement of the inclusive spectrum of cosmic electrons and positrons (all-electron) up to the multi-TeV region, where the shape of the spectrum can indicate the presence of nearby cosmic-ray sources or dark matter signatures. In this contribution, the analysis procedure that led to a precise measurement of the all-electron flux up to several TeV with the full statistics collected by the CALET experiment is presented and results are briefly discussed
Unveiling the origins of steep decay in γ-ray bursts
No full textγ-ray bursts (GRBs) are cataclysmic transient events which release most of their energy in the keV-MeV range. GRBs are originated from internal dissipation of the energy carried by ultra-relativistic jets launched by the remnant of a massive star’s death or a compact binary coalescence. With the discovery of gravitational waves associated to short GRBs, the investigation of this class of phenomena is crucial for the development of multi-messenger astrophysics. Though, we still have an incomplete understanding of where and how the radiation is generated in the jet. Performing a time-resolved spectral analysis of the X-ray tails of a
sample of 8 bright GRBs, we discover a unique relation between the spectral index and flux. This relation is incompatible with the common scenario used to interpret
X-ray tails, and requires to be explained with the adiabatic cooling of the emitting particles, suggesting a proton-synchrotron origin of the GRB emission
Endurance of mesoscopic twin-beam states propagating in noisy channels
No full textQuantum resources can improve the quality and security of data
transmission. Here we prove, both theoretically and experimentally, that mesoscopic twin-beam states of light are robust against loss and noise sources, thus opening new
perspectives in the implementation of Quantum Communication protocols
Tunneling transport of atomic Fermi gases across the superfluid phase transition
No full textIn this article, I review on two recent experiments on tunneling transport of atomic Fermi superfluids. By injecting controlled currents in a tworeservoir system coupled through a thin barrier, Josephson critical currents are directly accessed and employed to extract the condensed fraction of strongly interacting fermionic superfluids. At finite temperature, Josephson supercurrents are observed to breakdown when approaching the critical temperature of the superfluid phase transition, thus demonstrating them as a reliable probe of condensation at any temperature. Furthermore, the study of resistive currents reveals the importance of Bogoliubov-Anderson sound modes in the conduction of a unitary gas, increased by the phonon-condensate coupling at low temperature. These works highlight how transport measurements can unveil both the coherence properties and the role of excitations in quantum matter
DFT investigation of mercaptobenzamide inhibitors effects on the HIV NCp7 protein: A structural study
No full textThe mercaptobenzamide (MB) molecular mechanism of action on
the HIV Zn finger Nucleocapsid protein (NCp7), has recently attracted research interest, in order to develop a new class of effective and well tolerated HIV antiviral drugs, able to overcome virus escape strategies. The exact mechanism of MB on NCp7 is still not fully understood, and moreover it is heavy influenced by the specific functional groups in the MB aromatic ring and chain. Our approach to this biological
problem is to adopt a computational framework based on the density functional theory (DFT) for the structural study to investigate with atomistic resolution the action mechanism of MB molecules on NCp7
A feasibility study of tomato fruit quality assessment and traceability by X-ray fluorescence spectroscopy and statistical analysis
No full textX-ray fluorescence (XRF) measurements were performed on dried tomato samples coming from “Pachino district”, a geographical area recognized by the European Community with the “Protected Geographical Indication” (PGI) label. The purpose of this study is to establish a protocol for in-situ analysis in order to provide a fast and reliable technique for quality assessment and traceability of PGI products. Experimental data were studied by using Principal Component
Analysis. The results show the presence of several characterizing elements, which establish a clear fingerprint pattern associated with the geographical origin of this
product. Implications and perspectives in applying XRF analysis in order to disentangle tomato samples coming from different Sicilian geographical areas will be discussed