We study properties of an interaction between two clusters within the resonating group method. Due to the Pauli principle, a cluster-cluster interaction is a nonlocal potential within the standard version of the resonating group method. We employed the algebraic version of the method, which involves a complete basis of oscillator functions to expand a two-cluster wave function. In the...
Nuclear cluster structure often appears in the spectrum of light nuclei. The role of the nuclear clustering in the electric-dipole (E1) transitions is of great interest since they are closely related to important astrophysical reactions. Recently, an interesting speculation on the E1 excitation mechanism was made in the measurement of the photoabsorption cross section of 6Li that implied the...
We develop a new numerical method to construct an orthonormal basis of properly symmetrized hyperspherical harmonic functions [1]. Refined algorithms for calculating the transformation coefficients between hyperspherical harmonics based on different sets of Jacobi coordinates are described. A method to extract a maximal set of linearly independent hyperspherical states from a highly redundant...
The low energy collision of three- and four-neutrons is studied using the adiabatic hyperspherical representation, aimed at understanding whether low energy resonances might exist. This study is motivated by the recent experimental claim of an observation of a four neutron resonance [Kisamori et al., 2016]. From the theoretical side, several studies haven been reported, however, the...
