Advances in Radioactive Isotope Science

Four-body Continuum Effects in d+11Be Elastic Scattering

29 May 2017, 14:25

25m

Plenary-Longs Peak

Invited Presentation

Speaker

Dr Pierre Descouvemont (Universite Libre de Bruxelles)

Description

The main goal of the Continuum Discretized Coupled Channel (CDCC) method is to solve the Schrödinger equation for reactions where the projectile presents a cluster structure, and a low dissociation energy. The CDCC method has been introduced forty years ago [1] to describe deuteron induced reactions. Owing to the low binding energy of the deuteron, it was shown that including continuum channels significantly improves the description of d+nucleus elastic cross sections [1, 2]. The simplest variant of CDCC describes scattering of a two-body nucleus with a structureless target, but extensions to three-body projectiles have been performed recently (see, for example, ref. [3]). The projectile continuum is approximated by a finite number of square-integrable states, up to a given truncation energy. We present here a new development of the CDCC method, which aims at describing reactions where the projectile and the target have a low separation energy. This leads to four-body (or more) calculations. Since continuum states are included in both colliding nuclei, the number of channels can be extremely large. We solve the coupled-channel system by using the R-matrix method on a Lagrange mesh [4]. A first application is presented for d+11Be elastic scattering and breakup, which have been measured recently at Ecm=45.5 MeV [5]. The 2H and 11Be nuclei are defined by 2H=p+n and 11Be=10Be+n structures. We choose the Minnesota potential [6] as nucleon-nucleon interaction, and the Koning-Delaroche global potential [7] as nucleon-10Be optical potentials. We show that including continuum states of 2H and of 11Be is necessary to reproduce well the experimental data. References: [1] G. H. Rawitscher, Phys. Rev. C9 (1974) 2210. [2] M. Yahiro et al., Prog. Theor. Phys. Suppl. 89 (1986) 32. [3] T. Matsumoto et al., Phys. Rev. C70 (2004) 061601. [4] P. Descouvemont and D. Baye, Rep. Prog. Phys. 73, (2010) 036301. [5] J. Chen et al. , Phys. Rev. C94 (2016) 064620. [6] D.R. Thompson, M. LeMere, and Y.C. Tang, Nucl. Phys. A286 (1977) 53. [7] A.J. Koning and J.P. Delaroche, Nucl. Phys. A713 (2003) 231.