SWANLOP: Scattering waves off nonlocal optical potentials in the presence of Coulomb interactions

We introduce the package SWANLOP to calculate scattering waves and corresponding observables for nucleon elastic collisions off spin-zero nuclei. The code is capable of handling local and nonlocal optical potentials superposed to long-range Coulomb interaction. Solutions to the implied Schrödinger integro-differential equation are obtained by solving an integral equation of Lippmann–Schwinger type for the scattering wavefunctions, ψ = ϕ_C + G_C U_S ψ, providing and exact treatment to the Coulomb force Arellano and Blanchon (2019). The package has been developed to handle potentials either in momentum or coordinate representations, providing flexible options under each of them. The code is fully self-contained, being dimensioned to handle any A >= 4 target for nucleon beam energies of up to 1.1 GeV. Accuracy and benchmark applications are presented and discussed.

本报告推介SWANLOP软件包，旨在计算核子与自旋为零的核发生弹性碰撞时的散射波及其相应的可观测量。该软件包能够处理叠加在长程库仑相互作用之上的局部和非局部光学势。通过求解Lippmann-Schwinger类型的积分方程，获得散射波函数ψ的解，ψ = ϕ_C + G_C U_S ψ，从而对库仑力进行精确处理（Arellano和Blanchon，2019）。软件包的开发旨在处理动量或坐标表示下的势，为每种表示方式提供灵活的选项。代码完全自包含，可处理任何A≥4的目标，适用于高达1.1 GeV的核子束能量。本文将展示并讨论其精度和基准应用。