Detailed study of the eikonal reaction theory for the breakup of one-neutron halo nuclei

Abstract

Background: One-neutron removal reactions are used to study the single-particle structure of unstable nuclei, and in particular the exotic halo nuclei. The eikonal reaction theory (ERT) has been developed by Yahiro, Ogata, and Minomo [Prog. Theor. Phys. 126, 167 (2011)] to include dynamical effects, which are missing in the usual eikonal description of these reactions. Encouraging results have been obtained for total breakup cross sections in comparison to more elaborate reaction models. Purpose: We extend these comparisons to more differential breakup cross sections expressed as functions of the relative energy or parallel momentum between the core and halo neutron. Method: ERT predictions of these cross sections are compared to state-of-the-art calculations. Results: The hypotheses upon which the ERT is based are confirmed and their range of validity is made clearer. The actual ordering of the evolution operators affects ERT differential cross sections and a specific choice leads to excellent agreement with the reference calculation. Dynamical effects in the treatment of the neutron-target interaction can be significant in the parallel-momentum observable. Conclusions: The role of the different interactions in the dynamics of breakup reactions of one-neutron halo nuclei are better understood and improvements to the ERT are suggested.

Halo effective field theory analysis of one-neutron knockout reactions of Be11 and C15

“…The n- 9 Be optical potential of Bonaccorso and Charity [44] produces a slightly less asymmetric peak than Weppner's [43]. Albeit not statistically significant, this hints at the influence of the n-T interaction in those reactions dynamics [52].…”

Sensitivity of one-neutron knockout to the nuclear structure of halo nuclei

“…This simple linear dependence between the knockout cross sections and the mean square radius of the overlap function ⟨r 2 ⟩ can be understood analytically from the expressions of their contributions (2) and (3) at leading order. For projectiles with large core-to-neutron mass ratio, R cT ∼ R. The nuclear part of the c-T interaction thus plays a negligible role in the dynamics and is mainly inducing absorption at small R, i.e., at small impact parameters b [26,27]. Because knockout reactions are measured at intermediate energy, U nT /(hv) remains small and we can approach the eikonal phase S nT (4) by the first terms of its Taylor expansion.…”