[Show abstract][Hide abstract] ABSTRACT: We construct a 5D space in which conservation laws are always and absolutely valid. This general result holds also scaling
in 4D space even inducing, when necessary, changes of topology. The inequality of representations of physical laws in 4D and
in 5D generalized spaces is founded not on phenomenological but on mathematical results. Essentially, the mechanism is based
on the fact that we take into account also transformations where the Jacobian of the change of variables can assume null values.
We derive that stress-energy and metric tensors, due to Bianchi identities, are always conserved through the mechanism presented
in the following based on the fact that we introduce transformations with null Jacobian in the space definition. Moreover,
in the case of metric tensor, conservation is a necessary feature in order to have physically defined theories.
Rendiconti del Circolo Matematico di Palermo 05/2004; 53(2):272-282.
[Show abstract][Hide abstract] ABSTRACT: We investigate the weak-field limit of scalar-tensor theory of gravity and show that results are directly depending on the coupling and self-interaction potential of the scalar field. In particular, corrections are derived for the Newtonian potential. We discuss astrophysical applications of the results, in particular the flat rotation curves of spiral galaxies.
International Journal of Modern Physics D 01/2004; 13:359-371. · 1.03 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We discuss the phase-space of conservation laws in Lagrangian and Hamiltonian formalism from a very general point of view deriving all the geometrical properties of this reduced configuration space. Such a mathematical approach, based on an integration of the system dependent on the inequality between the number of dimensions in the configuration space and the number of conservation laws, is extremely useful in connection to the derivation of a General Conservation Principle (from which particular conservation laws can be derived). Properties and behaviours of general solutions are discussed in relation to the existence of first integrals of motion.
[Show abstract][Hide abstract] ABSTRACT: Singularity free cosmologies, depending on the form of gravitational coupling and interaction potential, are derived in the framework of (n+1)-dimensional scalar-tensor theories of gravity. The results are matched with cosmological observations giving rise to realistic scenarios where the observed acceleration of cosmic fluid is recovered. Furthermore, being the solutions singularity free, the approach could work also at early epochs showing a general validity of the model.
International Journal of Modern Physics D 01/2004; 13:717-737. · 1.03 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This paper reports observations of the absolute momentum differential fluxes of negative pions and muons between 4 and 15 GeV/c and between 0.3 and 15 GeV/c, respectively, at an atmospheric depth of 5 g . The data have been collected by the balloon-borne experiment MASS (matter - antimatter space spectrometer) launched from Prince Albert (Canada) where the geomagnetic cut-off is 650 MV/c. The instrument was flown on the 5th of September 1989, the duration of the flight was 5.5 hours at an altitude of more than 117 000 ft. The measured fluxes are compared to calculations. The muon spectrum follows a power law in momentum with a spectral index of 2.36 above 2 GeV/c.
Journal of Physics G Nuclear and Particle Physics 12/1998; 22(1):145. · 5.33 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Using a superconducting magnet spectrometer, we have measured the energy spectra of electrons, positrons, and protons at ground level at an atmospheric depth of 945 g/cm(2). The differential energy spectrum of the electron component has been determined in the momentum interval between 0.1 and 2.0 GeV/c. This spectrum can be described by two power laws, one below 600 MeV with a spectral index of -1.8 +/- 0.1 and the other above this energy with an index of -2.9 +/- 0.2. The absolute flux values measured here are not in agreement with the earlier results. The fraction of positrons varies from a value of 0.45 at 200 MeV to about 0.5 above 1 GeV, which is consistent with the theoretical expectation. The momentum dependence of the e/mu ratio in the region between 0.25 and 2.0 GeV/c is proportional to p(-2.2), and it appears that the soft component of the ionizing radiation might dominate at ground level at kinetic energies below about 70 MeV. The proton energy spectrum has been determined as a power law in kinetic energy between 2.9 and 19.1 GeV with a spectral index of -2.66 +/- 0.26. The p/mu ratio obtained from this experiment seems to have a steeper momentum dependence than from previous experiments.
Journal of Geophysical Research 01/1995; 100(A12):23515-23522. · 3.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A ballon-borne magnet spectrometer system was flown for 5.5 hr at an
altitude of more than 117,00 feet from Prince Albert, Saskatchewan
(Canada), on 1989 September 5, when the Newark neutron monitor rate was
2952. The instrument was a modified version of the one used to observe
antiprotons in 1979. The most significant modification was the addition
of an imaging calorimeter, 7.33 radiation lengths thick. Inclusion of
the calorimeter has significantly improved the ability to distinguish
electrons and positrons from the other constituents of the cosmic rays.
The absolute electron flux has been determined in the energy interval
1.3-26 GeV. The electron spectrum at the top of the atmosphere was found
to be Je- = 177E-(3.15+/-0.13) electrons/ sq m/(sr
s GeV) in the energy range 4.0-26 GeV. Below 4 GeV, the spectrum showed
flattening, which is consistent with the effect of solar modulation. The
e(+)/(e(+)+e(-)) ratio was found to be (0.11 +/- 0.03) in the energy
range 5.2-13 GeV.
The Astrophysical Journal 11/1994; 436:769-775. · 6.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The silicon sampling calorimeter presented is conceived as a fine grained imaging device to carry out studies of the anti-matter component in the primary cosmic radiation; it will be used in balloon payload program starting in 1993. The first sampling layer (48×48 cm2) of this silicon calorimeter has been completed and successfully tested. We report the first results form studies performed at the CERN PS t7 beam. The complete calorimeter contains 20 xy sampling layers (strip pitch 3.6 mm) interleaved with 19 showering material planes (tungsten 0.5 X0). This allows to picture the transverse distributions of the shower in both coordinates at each sampling. The outstanding imaging capabilities reflects in high particle identification power. Preliminary results from beam tests performed with antiprotons at 3.5 GeV on a tower prototype of the calorimeter are reported.
[Show abstract][Hide abstract] ABSTRACT: We have determined the momentum spectrum and charge ratio of muons in the region from 250 MeV/c to 100 GeV/c using a superconducting magnetic spectrometer. The absolute differential spectrum of muons obtained in this experiment at 600 m above sea level is in good agreement with the previous measurements at sea level. The differential spectrum can be represented by a power law with a varying index, which is consistent with zero below 450 MeV/c and steepens to a value of -2.7 +/- 0.1 between 20 and 100 GeV/c. The integral f1ux of muons measured in this experiment span a very large range of momentum and is in excellent agreement with the earlier results. The positive to negative muon ratio appears to be constant in the entire momentum range covered in this experiment within the errors and the mean value is 1.220 +/- 0.044. The absolute momentum spectrum and the charge ratio measured in this experiment are also consistent with the theoretical expectations. This is the only experiment which covers a wide range of nearly three decades in momentum from a very low momentum.
Journal of Geophysical Research-Space Physics. 01/1993; 98(A3):3501-3507.
[Show abstract][Hide abstract] ABSTRACT: This report presents the results obtained with a prototype silicon-tungsten (Si-W) electromagnetic calorimeter, conceived as a fine-grained imaging device to carry out studies of the antimatter component in primary cosmic radiation. The calorimeter prototype contains 20 x, y sampling layers interleaved with 19 showering material planes. One sensitive layer is obtained with two silicon strip detectors (Si-D) (60 × 60) mm2, each divided into 16 strips, 3.6 mm wide; the two detectors are assembled back to back with perpendicular strips. This allows the transverse distributions of the shower in both coordinates at each sampling (0.5 X0) to be pictured. The basic characteristics of the design and the experimental results obtained on a test beam at the CERN proton synchrotron (PS) for electrons and pions are reported. The main results presented are the response of the calorimeter to the electron at various energies (1-7 GeV), and the transverse shower profiles at different calorimeter depths as well as the patterns of the electromagnetic shower and those of the interacting and non-interacting pions. The capability of the calorimeter in measuring the direction of the incoming electromagnetic particle from the pattern of the shower has been evaluated at different energies. These results are encouraging in view of the possible use of this detector to search for high-energy gamma sources in space.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 01/1993; 333(2-3):560-566. · 1.14 Impact Factor