Clusters, Halos, And S-Factors In Fermionic Molecular Dynamics*

Hans Feldmeier,Thomas Neff,C Simenel,A Wallner,T Kibédi,M Evers,D Huy Luong,M Reed,M Srncik

doi:10.1051/epjconf/20136302021

Hans Feldmeier, Thomas Neff + Show 7 more

Open Access

https://doi.org/10.1051/epjconf/20136302021

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Abstract

In Fermionic Molecular Dynamics antisymmetrized products of Gaussian wave packets are projected on angular momentum, linear momentum, and parity. An appropriately chosen set of these states span the many-body Hilbert space in which the Hamiltonian is diagonalized. The wave packet parameters - position, momentum, width and spin - are obtained by variation under constraints. The great flexibility of this basis allows to describe not only shell-model like states but also exotic states like halos, e.g. the two-proton halo in 17Ne, or cluster states as they appear for example in 12C close to the \alpha-breakup threshold where the Hoyle state is located. Even a fully microscopic calculation of the 3He(\alpha,\gamma)7Be capture reaction is possible and yields an astrophysical S-factor that compares very well with newer data. As representatives of numerous results these cases will be discussed in this contribution, some of them not published so far. The Hamiltonian is based on the realistic Argonne V18 nucleon-nucleon interaction.

Highlights

In Fermionic Molecular Dynamics antisymmetrized products of Gaussian wave packets are projected on angular momentum, linear momentum, and parity
To restore the symmetries the intrinsic basis states are projected on parity, angular momentum and total linear momentum
In a full Fermionic Molecular Dynamics (FMD) calculation the many-body Hilbert space is spanned by a set of N projected intrinsic basis states

Summary

Introduction

In Fermionic Molecular Dynamics antisymmetrized products of Gaussian wave packets are projected on angular momentum, linear momentum, and parity. In a full FMD calculation the many-body Hilbert space is spanned by a set of N projected intrinsic basis states While the leading intrinsic configuration of the ground state is very compact, and after projection on good angular momentum, essentially a shell model state filling the p3/2shell, the Hoyle state is a quantal superposition of three α-clusters arranged in a slightly opened triangle configuration, or one may regard it as a 8Be surrounded by an α-cluster, see upper part of Fig. 1.

Results

Conclusion