Three-body optical potentials in $(d,p)$ reactions and their influence on indirect study of stellar nucleosynthesis

TL;DR

This paper investigates uncertainties in $(d,p)$ reaction models caused by three-body effects, using adiabatic distorted wave approximation, and assesses their impact on indirect studies of stellar nucleosynthesis.

Contribution

It introduces a simple prescription for including energy-dependent optical potentials in three-body models and evaluates the resulting uncertainties in astrophysical reaction studies.

Findings

Model uncertainties are within 40% at 12 MeV deuteron energy.

Uncertainties can reach 100% at higher energies around 60 MeV.

The approach provides a practical way to estimate three-body effects in nuclear reactions.

Abstract

Model uncertainties, arising due to suppression of target excitations in the description of deuteron scattering and resulting in a modification of the two-body interactions in a three-body system, are investigated for several $(d,p)$ reactions serving as indirect tools for studying the astrophysical $(p,\gamma)$ reactions relevant to $rp$-process. The three-body nature of deuteron-target potential is treated within adiabatic distorted wave approximation (ADWA) which relies on dominant contribution from the components of the three-body deuteron-target wave function with small $n$-$p$ separations. This results in a simple prescription for treating the explicit energy-dependence of two-body optical potentials in a three-body system requiring nucleon optical potentials to be evaluated at a shifted energy with respect to the standard value of half the deuteron incident energy. In addition, the ADWA allows for leading-order multiple scattering effects to be estimated, which leads to a simple renormalization of the adiabatic potential's imaginary part by the factor of two. These effects are assessed using both nonlocal and local optical potential systematics for $^{26}$Al, $^{30}$P, $^{34}$Cl and $^{56}$Ni targets at deuteron incident energy of 12 MeV typical for experiments with radioactive beams in inverse kinematics. The model uncertainties induced by the three-body nature of deuteron-target scattering are found to be within 40$\%$ both in the main peak of angular distributions and in total $(d,p)$ cross sections. At higher deuteron energies, around 60 MeV, model uncertainties can reach 100\% in the total cross sections. A few examples of application to astrophysically interesting proton resonances in $^{27}$Si and $^{57}$Cu obtained using $(d,p)$ reactions and mirror symmetry are given.