# Halo breakup and the Coulomb-nuclear interference problem

## TL;DR

This study investigates how the Coulomb-nuclear interference in 8Li breakup reactions varies with the projectile's ground-state binding energy, revealing that Coulomb effects dominate and interfere destructively with nuclear forces, especially at low binding energies.

## Contribution

It demonstrates the dependence of Coulomb-nuclear interference on the projectile's binding energy and highlights the dominance of Coulomb breakup over nuclear breakup in these reactions.

## Key findings

- Coulomb breakup cross section is more sensitive to binding energy than nuclear breakup.
- Coulomb-nuclear interference can be significant even when nuclear contribution is small.
- Interference effects are mainly due to peripheral interactions where Coulomb and nuclear forces destructively interfere.

## Abstract

The Coulomb-nuclear interference is studied as a function of the projectile ground-state binding energy in the 8Li + 12C and 8Li + 208Pb breakup reactions, by considering an arbitrary range for the 8Li ground-state binding energies {\epsilon}b, varying from the experimental one 2.03 MeV down to 0.01 MeV. Regardless the target mass, we first show that the Coulomb breakup cross section is stronger dependent on {\epsilon}b than the nuclear breakup cross section, due to the long-range nature of the Coulomb forces and to the electromagnetic transition matrix elements. For example, in case of 8Li + 208Pb reaction at Elab = 60MeV, it is found that |{\sigma}_int|\simeq 4\times{\sigma}_nucl$, while ${\sigma}_Coul\simeq 35\times{\sigma_nucl}$. This shows clearly that small nuclear contribution in a Coulomb-dominated reaction does not imply insignificant Coulomb-nuclear interference. Such result can be mainly attributed to peripheral interference phenomenon, represented by a function of the binding energy, which determines the peripheral range of nuclear forces, where Coulomb and nuclear forces strongly interfere destructively.