Insights into the dynamics of breakup of the halo nucleus 11Be on a 64Zn target

A Di Pietro,A.M Moro,Jin Lei,R De Diego

doi:10.1016/j.physletb.2019.134954

A Di Pietro, A.M Moro + Show 2 more

Open Access

https://doi.org/10.1016/j.physletb.2019.134954

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Abstract

We reexamine the elastic and breakup observables of the Be11+64Zn reaction at the near-barrier energy of 28.7 MeV. The measured quasi-elastic data are compared with CDCC and extended CDCC (XCDCC) calculations, the latter including the effect of the 10Be deformation.The angular distribution of emitted 10Be fragments, reported in the original analysis of this experiment, along with newly extracted 10Be energy distributions, are compared with calculations for the elastic breakup and non-elastic breakup contributions. Elastic breakup, computed with CDCC, accounts for most of the observed yields. The remaining difference (∼20%) is attributed to non-elastic breakup events (neutron absorption or target excitation) as confirmed by calculations performed with the model of Ichimura, Austern and Vincent (1985) [14].Finally, the effect of post-acceleration in the energy distribution is investigated. This effect is well accounted for by the present CDCC calculations and, according to simple kinematical considerations, is estimated to be of the order of 1 MeV, and roughly independent of the scattering angle.

Highlights

The discovery of exotic atomic nuclei in the proximity of the proton and neutron drip lines constitutes one of the major milestones in nowadays nuclear physics
The measured quasi-elastic data are compared with Continuum–Discretized Coupled–Channels (CDCC) and extended CDCC (XCDCC) calculations, the latter including the effect of the 10Be deformation
The remaining difference (∼20%) is attributed to non-elastic breakup events as confirmed by calculations performed with the model of Ichimura, Austern and Vincent (1985) [14]

Summary

Introduction

The discovery of exotic atomic nuclei in the proximity of the proton and neutron drip lines constitutes one of the major milestones in nowadays nuclear physics. Deviations from experimental data evidence limitations of the structure description, the reaction dynamics or the effective interactions Among these deviations from the strict few-body picture, two of them have recently received particular attention, namely, (i) the so-called core excitations (CEX) and (ii) the presence of non-elastic breakup (NEB) contributions in the inclusive breakup observables. The evaluation of non-elastic cross sections can be more efficiently done making use of inclusive breakup models These were proposed in the 1980s [11,12,13,14,15] but they have not been fully tested and applied until recently [16,17,18]. We report on new experimental results of the same experiment not published before, corresponding to the energy spectra of the 10Be fragments These data are compared with CDCC and XCDCC calculations, using an augmented modelspace with respect to previous studies.

Experimental analysis

Theoretical framework

Comparison with data

Conclusions