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Role of pair-vibrational correlations in forming the odd-even mass difference
Get PDFThe Random-Phase-Approximation (RPA) amended NilssonStrutinskij theory, which successfully describes the pattern of binding energies of the nuclei with N ≈ Z and even A = N + Z, where N and Z are the numbers of neutrons and protons, is applied to nuclei with odd A in both the N ≈ Z region and the chain of Sn isotopes. The RPA correction contributes significantly to the calculated odd-even mass differences, most significantly in light nuclei
Towards nuclear structure with radioactive muonic atoms The nuclear charge radius of radioactive isotopes from measurements of muonic X-rays
Get PDFThe muX project at the Paul Scherrer Institut aims to perform highresolution muonic atom X-ray spectroscopy for the extraction of nuclear charge radii of radioactive isotopes that can be handled only in microgram quantities. Measurements of the absolute charge radii of high-Z radioactive elements are complementary to the measurements of relative differences in mean-square radii along the isotopic chain available from laser spectroscopy. One of the major limitations of atomic structure calculations is related with the uncertainty of the nuclear charge radius.
This is the case for the extraction of the Weinberg angle from atomic parity violation in 226Ra. A new approach to solve previous limitations of muonic atom X-ray
spectroscopy experiments is the application of multiple muon transfer reactions in a high-pressure hydrogen gas cell with a small admixture of deuterium. The validity
of this method has been demonstrated with a measurement with only 5 μg of gold
XYZ states and exotics at BESIII experiment
Get PDFThe charmonium spectroscopy in the last decades has been enriched of a new family of particle states that could not be assigned to the conventional charmonium behavior. The study of those states, commonly named XYZ states, is an important task of the BESIII (BEijing Spectrometer III) research activities. BESIII looks at the collision results of electron and positron and it can produce directly states with quantum number JP C = 1−− and study their cross-section at different energies in order to understand the production mechanism of several final states. Moreover, the low hadronic background allows BESIII to measure precisely
the transition of exotic states to conventional ones. Thanks to the large data set in the charmonium region, BESIII can determine the spin-parity of some of those
states. In this paper, the current study of exotic XYZ states at BESIII will be presented
Advancements in searches for third-generation supersymmetry using the ATLAS detector
Get PDFThe long search for supersymmetric particles in high-energy physics experiments is leading to the exclusion of huge portions of the parameters space available for the masses of third-generations squarks. On the study of these states is based the search of a solution to the hierarchy problem in the Standard Model (SM); either the confirmation or the exclusion of their existence at masses O(1TeV) will be the base to the evolution of the high-energy physics in the upcoming decades. An overview of results achieved by the ATLAS experiment during Run-II in pp collisions with centre-of-mass energy of 13 TeV is presented in the following and specific cases of production and decay of top and bottom squarks will be discussed
Neutrinos in neutron star mergers: Nucleosynthesis and kilonova
Get PDFThe recent detection of gravitational waves and electromagnetic signals from the merger of a binary neutron star has confirmed our basic understanding of how this catastrophic events occur. The detected kilonova signal is compatible with the radioactive decay of heavy nuclei synthesized via the rapid neutron capture process. However, the presence of an early blue component, in addition to a later redder emission, points to a non-trivial and non-homogeneous angular distribution of the properties of the ejecta powering the kilonova. Detailed, anisotropic modeling of the kilonova emission, largely based on the results of simulations of matter ejection from a binary merger including neutrinos, is able to explain the observed
emission. This confirms the central role of weak interactions in determining the composition and ultimately the opacity of the expanding ejecta
Development of Ultra-Fast Silicon Detectors for 4D-tracking
Get PDFUltra-Fast Silicon Detectors (UFSD) are thin silicon detectors, based on the Low-Gain Avalanche Diode (LGAD) technology, designed to perform 4Dtracking. The main features of UFSD are described, together with two different sets of measurement, which demonstrate that the innovative characteristics of these sensors allow achieving a time resolution of about 30 ps up to a fluence of φ = 1015 neq/cm2
Micro-TPC reconstruction performance for planar GEM detector with high-rate beam
Get PDFA new reconstruction method for the Micro Pattern Gas Detectors (MPGD) has been implemented, called Micro-TPC, and implemented for Gas Electron Multiplier (GEM) detectors. The possible dependence of the drift velocity on the presence of residual charge in high-rate conditions motivated the test performed with planar GEM at MAMI Facility in Mainz. In this work the Micro-TPC technique, the setup and the results of the test beam that allowed to find the optimal working conditions will be presented
ALPIDE for space applications: Power consumption
Get PDFALPIDE, a monolithic active pixel sensor developed for the ALIDE Inner Tracker upgrade, is studied as possible sensor unit for a space-borne particle tracker. The aspect of power consumption and heat dissipation is investigated
Cosmic collisions with the LHCb experiment
Get PDFThe antiproton production cross-section in p-He collisions at √sNN = 110 GeV is measured with the LHCb experiment at CERN. The results are important for the interpretation of the data collected by the space-borne experiments PAMELA and AMS for the antiproton fraction in cosmic rays. The potential of an indirect observation of dark matter is presently limited by the uncertainty on the antiproton production in interactions between cosmic rays and the interstellar medium
Photoactive semiconductor nanocrystals for surface protection of architectural stone
Get PDFThe unique size-dependent chemical-physical properties of semiconductor nanocrystals can be profitably applied to the field of cultural heritage protection. The present paper accounts for the realization of colloidal TiO2 nanocrystals based coatings, with controlled morphology, with the goal to convey new functional properties to the surfaces of monuments and buildings of cultural interest. In the present paper, we collected the chemical-physical characterization and the investigation of the photocatalytic activity of rod-like TiO2 nanocrystals (TiO2NRs) based coatings applied to the Pietra Leccese, a porous calcarenite stone, extensively used in Southern Italy monuments. The application of TiO2 NRs based coatings was realized by three different techniques: casting, dipping and spray-coating. The
coating resulted in a functional protective layer, with self-cleaning characteristics, as demonstrated by its photocatalytic activity, enabling a new generation of smart coatings