A search for an exotic natural radioactivity of lead nuclei, using nuclear emulsion sheets as detector, is described. We discuss the experimental set-up of a test performed at the Gran Sasso National Laboratory (Italy), the event simulation, data analysis and preliminary results.
The research activities in collaboration with Enzo Flaminio are summarized and discussed.
The first parts of the thesis recalls the main features of the large MACRO experiment at the underground Gran Sasso Laboratory. It then describes the atmospheric muons measured by the experiment and the selection criteria to obtain and analyze a larg
e sample of cosmic muons. The time series of MACRO muons was analyzed with two complementary approaches: search for the occurrence of bursts of muon events and search for periodicities in the muon time distribution. The Scan Statistics method was used in the first case and the Lomb-Scargle spectral analysis in the second case. The two techniques complete early analyses performed with folding methods. It is confirmed that the seasonal variation is the dominant periodic variation, and one also confirms the solar diurnal and sidereal modulations. A separate study concerns the analysis of the energy losses of the hypothetical Nuclearites in different materials and detectors; their importance for the searches performed by the MACRO and the SLIM experiments is discussed.
A short historical review is made of charged particle production at high energy proton synchrotrons and at pp and {p}p colliders. The review concerns mainly low p_t processes, including diffraction processes, and fragmentation of nuclei in nucleus-nu
cleus collisions. A short recollection is made of the first studies of high p_t processes. Conclusions and perspectives follow.
A brief general picture of the world, european and italian energy situations is made, analyzing several different energy sources and paying attention to the relations energy-quality of life, energy-environment and energy-health. Then will be discusse
d fossil fuels, renewable energies, the role of electric energy, nuclear energy, energy savings, the greenhouse effect, a possible sustainable development, the hydrogen economy and the risk and its perception. Then follow the conclusions and perspectives.
The Standard Model (SM) of Particle Physics was tested to great precision by experiments at the highest energy colliders (LEP, Hera, Tevatron, SLAC). The only missing particle is the Higgs boson, which will be the first particle to be searched for at
the new Large Hadron Collider (LHC) at CERN. The SM anticipated that there are 3 types of left handed neutrinos. Experiments on atmospheric and solar neutrinos (made in Japan, Italy, Canada, Russia and the US) have shown the existence of neutrino oscillations, which imply that neutrinos have very small mass differences and violate the conservation of individual leptonic numbers. Neutrino oscillations were verified in long baseline neutrino experiments (in Japan and in the USA); and cosmology has given reasonably precise indications on the sum of the neutrino masses. In this general lecture will be summarized some of the main properties of the SM and some of the main results obtained in the field and the experiments in preparation. Some of the main open questions will be briefly discussed.
The ANTARES underwater neutrino telescope, at a depth of 2475 m in the Mediterranean Sea, near Toulon, is taking data in its final configuration of 12 detection lines. Each line is equipped with 75 photomultipliers (PMT) housed in glass pressure sphe
res arranged in 25 triplets at depths between 100 and 450 m above the sea floor. The PMTs look down at 45^o to have better sensitivity to the Cherenkov light from upgoing muons produced in the interactions of high energy neutrinos traversing the Earth. Such neutrinos may arrive from a variety of astrophysical sources, though the majority are atmospheric neutrinos. The data from 5 lines in operation in 2007 yielded a sufficient number of downgoing muons with which to study the detector performances, the vertical muon intensity and reconstruct the first upgoing neutrino induced muons.
The nuclear track detector CR39 was calibrated with different ions of different energies. Due to the low detection threshold (Z/beta~6e) and the good charge resolution (sigma_Z ~ 0.2e for 6e < Z/beta <83e with 2 measurements), the detector was used f
or different purposes: (i) fragmentation of high and medium energy ions; (ii) search for magnetic monopoles, nuclearites, strangelets and Q-balls in the cosmic radiation.
New measurements of the total and partial fragmentation cross sections in the energy range 0.3-10 A GeV of Fe^{26+}, Si^{14+} and C^{6+} beams on polyethylene, CR39 and aluminum targets are presented. The exposures were made at Brookhaven National La
boratory (BNL), USA, and Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan. The CR39 nuclear track detectors were used to identify the incident and survived beams and their fragments. The total fragmentation cross sections for all targets are almost energy independent while they depend on the target mass. The measured partial fragmentation cross sections are also discussed.
The SLIM experiment was a large array of nuclear track detectors located at the Chacaltaya high altitude Laboratory (5230 m a.s.l.). The detector was in particular sensitive to Intermediate Mass Magnetic Monopoles, with masses 10^5 < M <10^{12} GeV.
From the analysis of the full detector exposed for more than 4 years a flux upper limit of 1.3 x 10^{-15} cm^{-2} s^{-1} sr^{-1} for downgoing fast Intermediate Mass Monopoles was established at the 90% C.L.
