Erratum: Reconciling Coulomb breakup and neutron radiative capture [Phys. Rev. C 96 , 015801 (2017)]

Abstract

Erratum: Reconciling Coulomb breakup and neutron radiative capture [Phys. Rev. C 96, 015801 (2017)]The idea to infer radiative-capture cross sections of astrophysical interest, viz. at low energy, from Coulomb-breakup measurements was first suggested by Baur et al. [1]. The latter reaction can be seen as an exchange of virtual photons between the initially bound projectile and the target and hence as the time-reversed reaction of the former in which the nucleus is synthesized by the fusion of two clusters and the emission of a photon. At the first order of the perturbation theory, it is possible to directly relate the Coulomb-breakup cross section to the radiative-capture one by a detailed balance [1][2][3]. Because breakup measurements can be performed at higher energies where the cross sections are higher and therefore easier to measure, many breakup experiments have been performed following this idea. Unfortunately, it has been shown later that significant higher-order effects in the breakup process spoil this nice picture [4,5].In Refs. [6,7], Summers and Nunes have suggested comparing accurate breakup calculations, i.e., including both the nuclear and the Coulomb interactions between the projectile and the target at all orders, to experimental data and to extract from this comparison the asymptotic normalization constant (ANC) for the bound state of the nucleus under investigation. This ANC can then be used to constrain radiative-capture calculations. They have tested their idea on the particular case of 15 C for which accurate measurements have been performed for both its Coulomb breakup [8] and its synthesis by radiative capture [9]. Their radiative-capture calculations, constrained by the Coulomb-breakup data, are in seemingly good agreement with the direct measurement [6,7]. A similar agreement has been obtained by Esbensen using a different model of the breakup reaction [10].In the original paper, we have pushed this idea further and studied its sensitivity to the description of the 14 C-n continuum. Albeit smaller than the role of the ANC of the ground state, this part of the description of the nucleus is not negligible as shown earlier in Ref. [11]. However, following Refs. [12,13], it is possible to account for this effect by selecting the breakup data at forward angle and low energy in the projectile continuum (see the original paper). In this way, it seemed that even better agreement could be obtained between direct and Coulomb-breakup estimates.This excellent agreement was obtained following the prescription of Summers and Nunes to rescale the low-energy data point, assuming it corresponded to a Maxwellian average on the neutron energy. Unfortunately, as pointed out by Esbensen and Reifarth [14], this is not the case. To be properly compared to the capture measurements, calculations should be averaged over the energy distribution of the neutron beams used in the experiment [15] (see Fig. 3 of Ref. [9]).In this Erratum, we perform this averaging in a systematic way for the 12 14 C-n potentials dev...

Introduction to Nuclear-Reaction Theory

“…In particular, this could spoil the extraction of an ANC for the initial ground state from the direct-and naive-comparison of calculations to data. A similar conclusion has been drawn in a recent work using a Halo-EFT description of the projectile [59].…”

Dissecting reaction calculations using halo effective field theory and ab initio input

“…Therefore, the confrontation of LO calculations to data cannot be used to directly extract an ANC for the 11 Be ground state, as already pointed out in Ref. [71].…”

C15 : From halo effective field theory structure to the study of transfer, breakup, and radiative-capture reactions

“…To properly confront these results with the data measured by Reifarth et al [25], we need to account for the distribution of the neutron energy in the incoming beam [71]. The values averaged over the neutron distributions shown in Fig.…”