Neutron removal from the deformed halo nucleus Ne31

Abstract

Experimental data on Coulomb breakup and neutron removal indicate that 31 Ne is one of the heaviest halo nuclei discovered so far. The possible ground state of 31 Ne is either 3/2 − coming from p-wave halo or 1/2 + from s-wave halo. In this work, we develop a treatable model to include deformed wave functions and a dynamical knockout formalism which includes the dependence on the nuclear orientation to study the neutron removal from 31 Ne projectiles at energies around E ≈ 200 MeV/nucleon. A detailed account of the effects of deformation on cross sections and longitudinal momentum distributions is made. Our numerical analysis indicates a preference for the 31 Ne ground state with spin parity 3/2 − .

Halo EFT for $^{31}$Ne in a spherical formalism

“…The preferred structure of a P -wave neutron halo with J P = 3/2 − was also obtained using a microscopic G-Matrix calculation [16] and a deformed Woods-Saxon potential for the neutron-core interaction [17]. A theoretical analysis of the ground state quantum numbers 31 Ne based on experimental data on Coulomb breakup and neutron removal reached the same conclusion [18]. Most recently, the Gamow shell model was applied to the Neon isotopes 26 Ne− 31 Ne [19].…”

Role of a high ground-state centrifugal barrier in the breakup of the 31Ne nucleus

“…Since early studies of these systems [1], this field, once dominated by light weakly-bound halo systems as exemplified by several recent studies (Refs. ) on the breakup dynamics of these systems, has witnessed increasing identification of weakly-bound heavy neutron-halo systems, such as and [35][36][37][38][39][40][41][42][43][44][45], located on the neutron-rich limit of the nuclear chart. Owing to the effect of the centrifugal barrier, halo features are manifest in low ( ) orbital angular momenta [46].…”

“…) [43,[47][48][49], experimental and theoretical studies have identified this nucleus as a neutron-halo system in the ground-state [41][42][43]45]. By studying the breakup of through both the and groundstates [44], it has been shown that the latter ( ) does…”

“…The study in Ref. [44] did not consider other reaction channels, such as elastic scattering, where the projectile halo features are also manifested. Even though a ground-state does not describe the halo structure of this nucleus, it provides an opportunity to examine how a large orbital angular momentum inhibits the manifestation of halo features in breakup reactions.…”

Exploring the structure of $^{29}$Ne

“…Further, 29−32 Ne are located well inside this island, providing exciting contenders for research in this area. In fact, both experimental and theoretical studies for 31 Ne have confirmed it as a halo nucleus with intruder neutron configuration [12,15,16,17,18].…”