Ab initio folding potentials for nucleon-nucleus scattering based on no-core shell-model one-body densities

Author(s)

Burrows, M. ; Elster, Ch ; Weppner, S. P. ; Launey, K. D. ; Maris, P. ; Nogga, A. ; Popa, G.

• Document type: Journal article
• Source: PHYSICAL REVIEW C; v. 99, n. 4, p. 14-pg., 2019-04-15.

Abstract

Background: Calculating microscopic optical potentials for elastic nucleon-nucleus scattering has already led to large body of work in the past. For folding first-order calculations the nucleon-nucleon (NN) interaction and the one-body density of the nucleus were taken as input to rigorous calculations in a spectator expansion of the multiple scattering series. Purpose: Based on the Watson expansion of the multiple scattering series we employ a nonlocal translationally invariant nuclear density derived from a chiral next-to-next-to-leading order (NNLO) and the very same interaction for consistent full-folding calculation of the effective (optical) potential for nucleon-nucleus scattering for light nuclei. Methods: The first order effective (optical) folding potential is computed by integrating over the nonlocal, translationally invariant NCSM one-body density and the off-shell Wolfenstein amplitudes A and C. The resulting nonlocal potential serves as input for a momentum-space Lippmann-Schwinger equation, whose solutions are summed to obtain the nucleon-nucleus scattering observables. Results: We calculate scattering observables, such as total, reaction, and differential cross sections as well as the analyzing power and the spin-rotation parameter, for elastic scattering of protons and neutrons from He-4, He-6, C-12, and O-16, in the energy regime between 100 and 200 MeV projectile kinetic energy, and compare to available data. Conclusions: Our calculations show that the effective nucleon-nucleus potential obtained from the first-order term in the spectator expansion of the multiple scattering expansion describes experiments very well to about 60 degrees in the center-of-mass frame, which coincides roughly with the validity of the NNLO chiral interaction used to calculate both the NN amplitudes and the one-body nuclear density. (AU)

• FAPESP's process: 17/19371-0 - Dyson-Schwinger and Bethe-Salpeter calculations in Euclidean and Minkowski space in QED and QCD
• Grantee: Tobias Frederico
• Support Opportunities: Research Grants - Visiting Researcher Grant - International