Tag Archives: Evento scientifico

The aim of this talk is to review several aspects of two-gamma physics in relation to the exclusive process gamma gamma -> pseudoscalar meson, described by a transition form factor, as a function of the squared transfer momenta of the two photons. On this basis, the motivation for this kind of research, as well as its current status from theoretical and experimental points of view, will be discussed, e.g., recent BaBar measurements of the double off-shell photon transitions to eta’ mesons.

The presentation will begin with a brief overview of the research activity carried out at the Horia-Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), Bucharest, Romania The seminar topic will focus mainly on the processes occurring in the rapid collisions of heavy-light ions such as 12C, 16O, 32S and 35Cl with thin (self-supporting) solid targets. The ionization and X-ray (characteristic and radiative electron capture-REC) cross sections from integral measurements of K and L X-ray yields have been determined. The measurements were performed at 9 MV FN Pelletron Tandem Accelerator of IFIN-HH. The measured X-ray cross-sections are useful in developing and testing theoretical models (such as PWBA + ECPSSR, SCA, geometric model, Stobbe formula for REC) and complements the existing database for atomic ionization cross-sections. They can have an important role in applied physics, such as elemental PIXE (Particle Induced X-ray Emission) analysis with heavy ions, heavier than proton. Within the last section of the seminar, I will discuss the PIXE method, along with other IBA techniques, which are used to characterize different type of materials. Thus, PIXE along with PIGE (particle-induced gamma-ray emission) and RBS (Rutherford backscattering spectrometry), are one of the "Total IBA" techniques, simultaneously applied in order to determine elemental concentrations and depth profiling of the thin films and various biological samples, with applications in materials physics and medicine. Certain measurements, on certain samples (such as antlers) have been obtained for the first time through the “total IBA”-type method, using the 3 MV Tandetron Accelerator of IFIN-HH, …

Motivated by an anomaly observed in the decay of an excited state of Beryllium by the Atomki collaboration, we study an extension for the Standard Model with a gauged U(1)’ symmetry. We show that this scenario complies with a variety of experimental results and is able to explain the potential presence of a resonant spin-1 gauge boson, Z’, with a mass of 17 MeV in the Atomki experimental data, for appropriate choices of U(1)’ charges and Yukawa interactions.

Axions and axion-like particles are excellent dark matter candidates, spanning a vast range of mass scales from the milli- and micro-eV for the QCD axion, to 1E-22 eV for ultralight axions in string theory. In some scenarios, inhomogeneities in the axion density lead to the formation of compact structures known as axion “miniclusters” and axion stars. I will first discuss astrophysical and cosmological constraints on axions at either end of this spectrum, using data from the cosmic microwave background anisotropies and the effects of miniclusters on the gravitational microlensing and on direct detection. I will then assess the formation and the evolution of axion stars in various astrophysical regimes.

The combination of precision space and time information in particle tracking has the capability of transforming how we design experiments, 4D tracking is being considered in the upgrade of the ATLAS, CMS and LHCb experiments at the High-Luminosity LHC, set to start data taking in 2024-25. Regardless of the type of solution chosen, space-time tracking brings benefits to the performance of the detectors by reducing the background and sharpening the resolution; it improves tracking performances and simplifies tracks combinatorics. Space-time tracking also allows investigating new physics channels, for example, it opens up the possibilities of new searches in long-living particles by measuring accurately the time of flight between the production and the decaying vertexes.

Overview Since their discovery in 1895, the detection of X-rays had a strong impact and various  applications in several fields of science and human life. Impressive efforts have been done to develop new type of detectors and new techniques, aiming to obtain higher precisions both in terms of energy and position. Depending on the applications, Solid State Detectors, Microcalorimeters and various types of Spectrometers provide nowadays the best performances as spectroscopic and imaging detectors. The now reachable few microns and meV precisions open the door towards ground breaking applications in fundamental physics, medical science, astrophysics, cultural heritage and several other fields. The aim of this workshop is to have an overview, from different communities and research fields, of the most recent developments in X-ray detection and their possible impacts in various sectors like, for example, exotic atoms measurements, quantum physics studies, XRF, XES, EXAFS, plasma emission spectroscopy, monochromators, synchrotron radiation, telescopes and space engineering. A special focus will be put on the role played by mosaic crystals of pyrolitic graphite which, thanks to their physical properties, may have promising applications in many of these fields. This workshop is organized in the framework of the VOXES project, supported and financed by the 5th National Scientific Committee of INFN in the framework of the Young Researcher Grant 2015, n. 17367/2015.   Main Topics: X-ray energy detectors X-ray position detectors Spectrometers X-ray optics Graphite based applications X-ray imaging X-rays in astrophysisc X-rays in nuclear physics Cultural heritage applications of X-rays Medical applications Conference …

Organometal Halide Perovskites such as MethylAmmonium Lead Iodide are opening new opportunity for solution-process high performing optoelectronic devices such as solar cells, photodetectors, light-emitting diodes etc. The success of such materials is based on the ideal direct band gap, good electron and hole diffusion lengths and the easy manufacture. Moreover, tuning of electronic and optical properties can be achieved by varying cation composition (Cs, Rb, FA, MA etc.) and halide composition (I, Br, Cl). One of the most successful application of such materials is in the field of solar cell where a certified efficiency of 22.7% has been achieved for single cells and 27.3% for tandem perovskite/silicon. I this talk I will review the main characteristics of the halide perovskites and the application to conventional optoelectronic devices showing possible applications in the field of high-energy physics.

Overview ICFDT is an interdisciplinary conference, jointly organized by INFN and ENEA Frascati laboratories, aimed at bringing together scientists, engineers and also experts from industries. Contributions are welcome from the frontiers of diagnostics in different areas of research: high energy and accelerator physics and technology, nuclear fusion plasmas, space and astrophysics research, medical applications, lasers physics and technology, etc., to discuss common interests in concepts and realization of measurement systems. Special focus of this 5th ICFDT edition will be on proposals/projects/ideas for novel measurement systems with a high degree of reliability and innovation to mark significant progress in the diagnostic techniques for Advanced Accelerators, Innovative Nuclear Fusion Devices, Metamaterials and the Detection of Fast and Ultra-fast Events. The ICFDT5 will have seven special and regular plenary sessions, a satellite meeting and a poster session (see Scientific Programme). Poster dim. 841 x 1.189 mm (A0) vertical. Important dates: 15 July 2018    Talk Acceptance Notification 31 July 2018    Early Registration Deadline 10 Sept. 2018  Poster Abstract Submission Deadline 14 Sept. 2018  Late Registration Deadline 3-5 Oct. 2018  Conference Convened

Almost one hundred years ago the Russian biologist A. Gurwitsch found that a weak ultra-violet radiation comes out from the living tissues and influences the mitotic activity of the neighboring organisms. He called this radiation “mitogenetic radiation”. However, this interesting result has been forgotten by the scientific community and the mitogenetic radiation was then considered as an artifact. With the improvement of the methods to detect weak level of radiation and the increase of understanding of quantum optics, there has been a renewed interest in this phenomenon with the works of Colli and Facchini in the 50s and F.A. Popp in the 80s. At the present this research is a new field called “biophotonics”. Biophotons are an endogenous production of ultra-weak photon emission in and from cells and organisms and this emission is characteristic of alive organisms. The essential characteristics of biophoton emission are the following: 1. The total intensity of the emission goes from several to some hundred photons per cm2 surface of the living system. 2. The spectral intensity seems to be quite flat within the range of at least 300 and 800 nm and does not show any defined peaks around some specific frequencies. 3. After excitation by white and/or monochromatic light the emission increases of almost a factor ten and relaxes to the normal values quite slowly following a hyperbolic function rather than an exponential low. 4. The photocount statistics that account for the probability of having n photons within some time interval seems to follow …