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

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.

Figure 1

Three-body model of the reaction and Jacobi set of coordinates. The projectile $P$, described as the $c-n$ two-body system, collides with the structureless target $T$. The $Z$ axis is chosen along the incoming beam.

Figure 2

Breakup cross section of ${}^{11}\mathrm{Be}$ as a function of the ${}^{10}\mathrm{Be}-n$ relative energy $E$ on (a) ${}^{12}\mathrm{C}$ at 67 MeV/nucleon and (b) ${}^{208}\mathrm{Pb}$ at 69 MeV/nucleon. The DEA reference calculation is compared to different implementations of the ERT: the original ERT Eq. (11), ${\mathrm{ERT}}^{\left(n\right)}$ Eq. (12) with $Z=0$, and ${\mathrm{ERT}}^{\left(c\right)}$ Eq. (13) with $Z=0$. The roles of $V_{cT}$ and $V_{nT}$ are also tested.

Figure 3

Cross sections as a function of the ${}^{10}\mathrm{Be}-n$ parallel-momentum for the diffractive breakup of ${}^{11}\mathrm{Be}$ on (a) ${}^{12}\mathrm{C}$ at 67 MeV/nucleon and (b) ${}^{208}\mathrm{Pb}$ at 69 MeV/nucleon. The results using various implementations of the ERT are compared to the reference DEA calculations. The roles of $V_{nT}$ and $V_{cT}$ are also explored.