A New Antisymmetrized Molecular Dynamics Approach to Few-Nucleon Systems

Abstract

A new method in the study of antisymmetrized molecular dynamics (AMD) is proposed. This method consists of a Jacobi-coordinate-basis AMD with the generator coordinate method (GCM). A simple example is presented for the case of in few-nucleon systems with the Volkov potential. Bound states for 2N, 3N, and 4N systems are compared with those obtained using the “primary AMD” and some other methods. We find this to be a promising method for investigating light nuclear systems. During the past decade, since the primary antisymmetrized molecular dynamics (AMD) was proposed, 1)–3) it has been successfully extended to systematic studies of neutron-rich nuclei, 4)–6) as well as excited states of nuclei. 7) Further developments of the AMD method have been realized by introducing several conventional ideas of conventional nuclear structure physics. 8)–19) The physical approaches mentioned above were formulated by making improvements of the AMD in Refs. 4)–7); for instance, a variational calculation was carried out after application of the spin parity projection (VAP) in order to investigate excited states 15) and the existence of exotic clusters in excited states of neutronrich nuclei. 16)–19) Another improvement realized through use of the superposition of selected Slater determinants was made in the AMD triple-S model, which can quantitatively describe properties of light nuclei. 10),11) These improvements were made in methods treating medium light nuclei in which the wave function is expressed in terms of a superposition of Slater determinants. However, this method has not yet been successfully applied to few-body problems. In order to allow for the application of the AMD method to few-body and very light nuclei, we present one modified AMD method which was developed using the Jacobi-coordinate-basis AMD plus the GCM technique. 20),21) One of the aims of this work is to introduce the N-body correlations in a “single Slater determinant”. The second is to remove the ambiguity of the zero-point oscillation energy. The third is to reduce the number of variational parameters in the AMD effectively with the GCM technique; using this technique, a very large number of the variational parameters can be fixed in the eigenvalue problem. Let us start from the trial wave function primary AMD. The wave function of N -nucleon system Ψ is given by