Toward a Microscopic Description of Nucleus-Nucleus Collisions.

Area of Science:

• Nuclear Physics
• Quantum Chromodynamics
• Computational Physics

Background:

• Understanding nucleus-nucleus elastic collisions is crucial for nuclear structure and reactions.
• Existing models often rely on phenomenological potentials, limiting predictive power.
• Ab initio methods offer a pathway to microscopic descriptions from fundamental interactions.

Purpose of the Study:

• To develop and present the first results of a comprehensive microscopic approach for nucleus-nucleus elastic collisions.
• To utilize a first-order multiple-scattering theory optical potential derived from nucleon-nucleon interactions.
• To compare calculated cross sections with experimental data for alpha collisions.

Main Methods:

• Derived an optical potential at first order in multiple-scattering theory.
• Folded projectile and target nuclear densities with the nucleon-nucleon t matrix.
• Employed chiral interactions consistently for the t matrix and nonlocal nuclear densities.
• Computed nuclear densities within the ab initio no-core shell model.

Main Results:

• Calculated cross sections for alpha collisions on Carbon-12 and Oxygen-16 at 100-300 MeV projectile energies.
• Achieved good agreement with experimental data for momentum transfer up to approximately 1.0 fm⁻¹.
• Observed a need for reduced imaginary contributions in the potential for higher momentum transfers.

Conclusions:

• The presented microscopic approach provides a reliable description of nucleus-nucleus elastic collisions at lower momentum transfers.
• The results highlight the importance of accurate nucleon-nucleon interactions and nuclear structure calculations.
• Further refinements, particularly in the imaginary part of the optical potential, are necessary for higher momentum transfers.