Matter and charge radius of6He in the hyperspherical-harmonics approach

Abstract

We present ab-initio calculations of the binding energy and radii of the two-neutron halo nucleus 6 He using two-body low-momentum interactions based on chiral effective field theory potentials. Calculations are performed via a hyperspherical harmonics expansion where the convergence is sped up introducing an effective interaction for non-local potentials. The latter is essential to reach a satisfactory convergence of the extended matter radius and of the point-proton radius. The dependence of the results on the resolution scale is studied. A correlation is found between the radii and the two-neutron separation energy. The importance of three-nucleon forces is pointed out comparing our results and previous calculations to experiment.

Emergence of rotational bands inab initiono-core configuration interaction calculations of the Be isotopes

“…3(d)], 10 Be natural parity excited band [ Fig. 4(b)], and 12 Be natural parity excited band [ Fig. 4(c)] -the quadruple moments and transition matrix elements are similarly consistent with the expected rotational values (Figs.…”

“…4(c)] -the quadruple moments and transition matrix elements are similarly consistent with the expected rotational values (Figs. 10, 14, and 15, respectively), with the exception that reduced strengths are found for the highest identified band member, at J = 8, in 12 Be.…”

“…The parity of the lowest allowed oscillator configuration may be termed the natural parity, and that obtained by promoting one nucleon by one shell the unnatural parity. Thus, the natural parity is negative for the odd-mass isotopes 7,9,11 Be, and positive for the even-mass isotopes 8,10,12 Be. While the lowest unnatural parity states normally lie at significantly higher energy than those of natural parity, they are calculated to lie within a few MeV of the lowest natural parity states in the isotopes 9,11 Be [29], and are thus included in the present discussion of these nuclei.…”

“…However, recent developments in large-scale calculations have brought significant progress in the ab initio description of light nuclei (e.g., Refs. [9][10][11][12][13][14]). We may now therefore hope to observe the emergence of collective phenomena directly from first principles, that is, in a fully ab initio calculation of the nucleus, as a many-body system in which all the constituent protons and neutrons participate, with realistic interactions.…”

New applications of renormalization group methods in nuclear physics

“…[92], the binding energy and radii of the two-neutron halo nucleus 6 He have been studied in the hyperspherical harmonics approach based on low-momentum NN interactions. The RG evolution has been found to be essential to obtain converged results of the extended matter radius and of the point-proton radius.…”