arXiv subjects
Publications and source records attributed to I. Lazanu.
Starting from the general Lindhard theory describing the partition of particles energy in materials between ionisation and displacements, analytical approximate solutions have been derived, for media containing one and more atomic species, for particles identical and different to the medium ones. Particular cases, and the limits of these equations at very high energies are discussed.
A comparative theoretical study of the damages produced by protons and pions, in the energy range 50 MeV - 50 GeV, in diamond, is presented. The concentration of primary defects (CPD) induced by hadron irradiation is used to describe material degradation. The CPD has very different behaviours for protons and pions: the proton degradation is important at low energies and is higher than the pion one in the whole energy range investigated, with the exception of the Delta33 resonance region, where a large maximum of the degradation exists for pions. In comparison with silicon, the most investigated and the most studied material for detectors, diamond theoretically proves to be one order of magnitude more resistant, both to proton and pion irradiation.
The energy dependence of the concentration of primary displacements induced by protons and pions in diamond has been calculated in the energy range 50 MeV - 50 GeV, in the frame of the Lindhard theory. The concentrations of primary displacements induced by protons and pions have completely different energy dependencies: the proton degradation is very important at low energies, and is higher than the pion one in the whole energy range investigated, with the exception of the delta33 resonance region. Diamond has been found, theoretically, to be one order of magnitude more resistant to proton and pion irradiation in respect to silicon.
A re-analysis of some $\bar{p}p$ and $\bar{p}n$ data, at rest and in flight, obtained in bubble chamber experiments, is presented. The ($π^{+}π^{-}$) and ($K_{S}K_{S}$) final states for the channels (2$π^{-}π^{+}$) and ($K_{S}K_{S}π$) are investigated. Evidence for a narrow meson resonance structure, cautiously suggested as $f_{0} (1500)$, is given. In the ($π^{+}π^{-}$) invariant mass distribution from $\bar{p}n$ annihilations in flight, using the method of difference spectra, a very clear evidence for $ρ^{0}, f_{2}(1270)$ and $f_{0} (1500)$ is first time obtained from these data. This re-analysis suggests that the old bubble chamber data can still provide relevant information on the annihilation process in liquid hydrogen and deuterium, and can elucidate controversial aspects of the annihilation mechanism.