[en] The recent results on charm meson physics are reviewed. The experimental setup and the procedures used to analyse the data are shortly described. The measurement of the relative branching ratios in hadronic two body decays are presented and compared with other data and theoretical predictions. (author)

[en] Present status of the IFIN-HH Cyclotron accelerator in Bucharest is reported together with main parameters of the beams delivered over the last two years for different projects. Several target assemblies developed and routinely used in dedicated experiments are illustrated. Further possibilities for new experiments and/or for increasing performances on the existing projects are briefly analyzed. (authors)

[en] The Time Differential Perturbed Angular Distribution (TDPAD) method in connection with long-lived Positron Life-Time Spectroscopy (PLTS) have been used to observe 'quantum beat' spin oscillations of positronium atom in an external magnetic field. Our results offer an encouraging hint toward a new method of condensed matter investigation by PLTS. Similarities with Muonium Spin Rotation (μSR) method are suggested. (authors)

[en] Portland cement pastes consist of many crystalline and non-crystalline phases in various ranges of sizes (nm and mm scale). The crystalline phases are embedded in amorphous phases of the hydration products. We investigated the structural changes of hydrating phases in the time interval of 1-30 days at Budapest Neutron Center's SANS diffractometer. The small angle neutron scattering of Portland cements prepared with a water-to-cement ratio from 0,3 to 0,8 gave us information about the microstructure changes in the material. Fractals were a suitable way for structure modelling. The variation of fractals size depending on the preparation-to-measurement time interval and water-to-cement ratio could be observed. (authors)

[en] The Doppler-broadening technique requires an energy-dispersive system. Compared with the angular correlation technique, a compact and relatively simple setup is possible and, thus spectrometers are used in almost all positron laboratories. The energy broadening of the annihilation line is measured by a high-resolution energy-dispersive detector system. The paper describes the principia of this method, experimental arrangement used, and data treatment. (authors)

[en] A master equation for the deformed quantum harmonic oscillator interacting with a dissipative environment, in particular with a thermal bath, is derived in the microscopic model by using perturbation theory, for the case when both the Hamiltonian of the system and the interaction Hamiltonian are deformed. The coefficients of the master equation and of equations of motion for observables depend on the deformation function. The steady state solution of the equation for the density matrix in the number representation is obtained and shown that it satisfies the detailed balance condition. The equilibrium energy of the deformed harmonic oscillator, calculated in the approximation of small deformation, does not depend on the deformation of interaction operators. (author)

[en] The results of the measurement of three kaonic nitrogen X-ray transitions, using the DEAR (DAFNE Exotic Atoms Research) setup at the DAFNE collider at Frascati, are reported. The measurement represents the first stage of DEAR scientific programme, which aims at the precise determination of the KN scattering lengths by measuring the shift and broadening, due to strong interaction, of the K_α lines in kaonic hydrogen and kaonic deuterium. (author)

[en] In the absence of a quantum field theory for gravitation, it is interesting to investigate the behaviour of a quantum object, i.e. a fermion, in curved spacetimes. We discuss the relativistic spin-1/2 particles in pseudo-classical models involving anticommuting Grassmann variables for the spin degrees of freedom. The constants of motion are expressed in terms of Killing vectors and Killing-Yano tensors. Passing from the spinning spaces to the Dirac in curved backgrounds we point out the role of the Killing-Yano tensors in the construction of the Dirac-type operators. The general results are applied to the case of the four-dimensional Euclidean Taub-Newman-Unti-Tamburino space and the Minkowski spacetime. (author)

[en] The nuclear systems with A = even and 2 neutrons (neutron gaps) in the N = 82 valence shell are described according to the cluster-vibrator coupling model. The energy spectra and electromagnetic properties are calculated and compared with recent experimental data obtained with radioactive ions. A comparison is also made with other QRPA and SM nuclear models. (authors)

[en] The preliminary incoherent neutron scattering on TGS polycrystalline sample were carried out at NEAT BENSC -HMI. The inelastic scattering part of the spectra remains practically unchanged on going through the critical point. The quasielastic peak is described by the sum of the EISF and two Lorentzians with different widths: 0.1 meV and 0.61 meV respectively. For a fixed Q the both widths change dramatically on going through T_c. From the analysis of the EISF as a function of momentum transfer Q we concluded that the mobile protons are moving on the surface of two spheres of different radius: 0.16 A and 3.1 A, respectively. (authors)