The interplay of nuclear and Coulomb effects in proton breakup from exotic nuclei

TL;DR

This study analyzes the different dynamical mechanisms involved in proton breakup from exotic nuclei, emphasizing the interference between Coulomb and nuclear effects across various targets and energies.

Contribution

It provides a detailed quantitative analysis of the separate and combined effects of Coulomb recoil, direct Coulomb, and nuclear breakup mechanisms, including their interference, in proton breakup reactions.

Findings

Direct Coulomb breakup yields larger cross sections than recoil effects.

Nuclear diffraction contribution varies with target.

Interference effects significantly influence measured observables.

Abstract

This paper gives new insight to the study of dynamical effects in proton breakup as compared to neutron breakup from a weakly bound state in an exotic nucleus. Following our recent work [Ravinder Kumar and Angela Bonaccorso, Phys. Rev. C84 014613 (2011)] there has been some discussion in the literature [B. Paes, J. Lubiana, P.R.S. Gomes, V. Guimar\~aes, Nucl. Phys. A890 1 (2012); Y. Kucuk and A. M. Moro, Phys. Rev. C86 034601 (2012)], thus in order to clarify and asses quantitatively which mechanism would dominate measured observables, we study here several reaction mechanisms separately but also their total including interference. These mechanisms are: the recoil effect of the core-target Coulomb potential which we distinguish from the direct proton-target Coulomb potential and nuclear breakup, which consists of stripping and diffraction. Direct Coulomb breakup typically gives cross sections about an order of magnitude larger than the recoil term and the amount of nuclear diffraction vs. Coulomb depends on the target. Thus for each mechanism the absolute values of breakup cross sections and parallel momentum distributions for 8B and 17F projectiles calculated on a light and a heavy target in a range of intermediate incident energies (40-80A.MeV) are presented. Furthermore we study in detail the interference among the two Coulomb effects and nuclear diffraction. The calculation of the direct and recoil Coulomb effects separately and of their interference is the new and most relevant aspect of this paper.