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arXiv · 2108.13717

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

M. J. Dinmore·N. K. Timofeyuk·J. S. Al-Khalili
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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 $(p,γ)$ 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.

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M. J. Dinmore, N. K. Timofeyuk, J. S. Al-Khalili. 2021-08-31. Three-body optical potentials in $(d,p)$ reactions and their influence on indirect study of stellar nucleosynthesis. https://doi.org/10.1103/physrevc.104.034614

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