Status of the ACCULINNA-2 project at FLNR

The project of a new and more powerful in-flight fragment separator ACCULINNA-2 at U-400M cyclotron in FLNR, JINR planned to build in addition to the existing separator ACCULINNA is presented. The new separator will provide high intensity RIBs in the lowest energy range (5÷50 MeV/nucleon) which is attainable for in-flight separators. The possibilities for the astrophysics studies at the proposed device are presented. ACCULINNA-2 separator is planned to be constructed in the years 2010-2015. The current status of the project is reported

New insight into the observation of spectroscopic strength reduction in atomic nuclei: implication for the physical meaning of spectroscopic factors.

Experimental studies of one-nucleon knockout from magic nuclei suggest that their nucleon orbits are not fully occupied. This conflicts a commonly accepted view of the shell closure associated with such nuclei. The conflict can be reconciled if the overlap between initial and final nuclear states in a knockout reaction are calculated by a nonstandard method. The method employs an inhomogeneous equation based on correlation-dependent effective nucleon-nucleon interactions and allows the simplest wave functions, in which all nucleons occupy only the lowest nuclear orbits, to be used. The method also reproduces the recently established relation between reduction of spectroscopic strength, observed in knockout reactions on other nuclei, and nucleon binding energies. The implication of the inhomogeneous equation method for the physical meaning of spectroscopic factors is discussed

Improved procedure to construct a hyperspherical basis for the N-body problem: Application to bosonic systems

A new procedure to construct hyperspherical harmonics is presented in which the matrix of the multidimensional hyperangular Laplacian is diagonalized in the single-particle oscillator basis. It is shown that this matrix can be constructed and diagonalized prior to the elimination of spurious states in small subspaces, and that calculations of only the two-body operators is required. As a result, the hyperspherical basis can be constructed much faster than in the procedure introduced earlier [N. K. Timofeyuk, Phys. Rev. C 65, 064306 (2002)], which is based on recursive elimination of hyperradial excitations. The applicability of the proposed method is demonstrated for the systems made of up to ten identical bosons with zero spin using two different two-body potentials. In particular, it has been applied to some α-particle nuclei for which the projection of their 0+ wave functions into the “condensed state wave function” have been calculated