V.G. Neudachin

Giant resonance of dipole absorption of γ-quanta by non-spherical light nuclei and spectroscopic data on excited one-particle levels

Abstract It has been shown 1) that the estimation of residual interactions by spectroscopic data on the lower states of nuclei determines, for average nuclei with A 1 f 7 2 shell are dealt with in connection with the discussion of spectroscopic data.

Geometrical positions of nucleon clusters in the nucleus

The method of directed orbitals known in quantum chemistry is used to formulate some general rules for determining the geometrical positions of alpha - clusters in a nucleus by a given set of Nilsson orbits or by shell configuration. As illustration certain excited states of /sup /sup 16/O and /sup 12/C are considered, and the geometry of the position of alpha -clusters in /sup 40/Ca is determined. Several critical remarks are made on the application of the alpha - model to light nuclei; the alpha model is erroneous in the description of /sup 16/O. (auth)

Determination by Eλ transitions of the extent of isolation of α-clusters in p shell nuclei

Abstract Earlier investigations 1,2 ) are extended by using experimental data on Eλ matrix elements to determine the extent of isolation of α-clusters in Be 9 , C 12 and O 16 . To solve this problem, a mathematical formalism for the nucleon cluster model (NCM) is developed and a sufficiently simple and accurate method is proposed for the interpolation between the shell model and the α-model in terms of a parameter characterizing the extent of α-cluster isolation 1 ).

Lower levels of O17 and F17 in the α-model of the nucleus

Abstract A method is presented for calculating one-particles states in the α-model by using a non-spherical potential similar to the Nilsson potential but with other properties of symmetry. The spectrum of the lower levels of O17 and F17 is calculated in the weak coupling scheme taking into account the interaction of the motion of the particle with the non-sphericity of the core and with vibrations, which is of essential importance. With certain values of the 2 parameters used in the calculation: the deformation parameter and the particle-vibrational coupling constant, the results are in good agreement with experiment. The lower levels of negative parity of the O17 or F17 system have small reduced widths and are rotational-vibrational states constructed on the single-particle orbits of the outer nucleon 1d and 2s with small admixtures of 1f and 2p. The calculation shows that the quadrupole moment of O17 and the lifetime of the level 1 2 + are almost entirely determined by the influence of the lower 2+ level of O14 with an energy 6.91 MeV.