Spectra of self-adjoint extensions and applications to solvable Schroedinger operators

We give a self-contained presentation of the theory of self-adjoint extensions using the technique of boundary triples. A description of the spectra of self-adjoint extensions in terms of the corresponding Krein maps (Weyl functions) is given. Applications include quantum graphs, point interactions, hybrid spaces, singular perturbations.Comment: 81 pages, new references added, subsection 1.3 extended, typos correcte

Recoil Studies in the Reaction of 12-C Ions with the Enriched Isotope 118-Sn

The recoil properties of the product nuclei from the interaction of 2.2 GeV/nucleon 12-C ions from Nuclotron of the Laboratory of High Energies (LHE), Joint Institute for Nuclear Research (JINR) at Dubna with a 118-Sn target have been studied using catcher foils. The experimental data were analyzed using the mathematical formalism of the standard two-step vector model. The results for 12-C ions are compared with those for deuterons and protons. Three different Los Alamos versions of the Quark-Gluon String Model (LAQGSM) were used for comparison with our experimental data.Comment: 10 pages, 6 figures, submitted to Nucl. Phys.

Formation of residual nuclei with medium mass number in the reaction of protons with separated tin isotopes

Abstract The mechanism of formation of residual nuclei in the mass region 42 A 81 in the reactions of protons with separated tin isotopes at three protons energies 0.66, 1.0 and 8.1 GeV was investigated. The absolute cross-sections of the residual nuclei were compared with the theoretical ones calculated by the standard cascade-evaporation and the intranuclear cascad plus statistical multifragmentation models (INC + SMM). It was shown that at E p = 8.1 GeV these nuclei may arise both from disintegration of the nucleus and as partners of several fragments

Nature and entropy content of the ordering transitions in RCo2

Differential scanning calorimetry experiments have been performed under magnetic field in R Co 2 Laves phases compounds ( R = Pr , Nd, Tb, Dy, Ho, and Er). The thermodynamical nature of the ferromagnetic transitions in Pr Co 2 and Nd Co 2 is clarified, after the controversy present in the literature about the character of their ordering transitions. The magnetocaloric effect in the compounds showing a first-order magnetostructural transition ( R = Dy , Ho, and Er) is characterized. The latent heat, L , and the entropy change at the transition, Δ S , have been studied by inducing the transition sweeping the temperature at a constant field and sweeping the field at a constant temperature. Results from calorimetric data show that L is essentially temperature independent, suggesting that the first order transitions in R Co 2 are dominated by the structural effects. The magnetocaloric effect has been also characterized from magnetization data and the results are in excellent agreement with those from calorimetric data. However, the corresponding values of Δ S for isothermal and isofield experiments differ significantly. We interpret the differences in terms of the broadness of the transitions and prove that the various Δ S values reported in literature for first-order transitions are not always directly comparable