R-matrix method and the nonlocal nucleon optical potential

Abstract

The calculable R-matrix method is applied to solve the Schr ̈odinger equationin the optical model (OM) analysis of the elastic nucleon-nucleus scatter-ing using a nonlocal nucleon optical potential (OP). The phenomenologicalnonlocal nucleon OP proposed by Perey and Buck (PB), and the two recentversions of the PB parametrization were used in the present OM study of theelastic nucleon scattering on 208 Pb and 27 Al targets at different energies. Thecomparison of the OM results given by the calculable R-matrix method withthose given by other methods confirms that the calculable R-matrix methodis an efficient tool for the OM study of the elastic nucleon-nucleus scatteringusing a nonlocal nucleon OP.

Rearrangement term in the folding model of the nucleon optical potential

“…This R-matrix method was recently extended [27,28] to include the Lagrange mesh and Gauss-Legendre quadrature integration that significantly simplify the numerical calculation. This method was tested in our recent OM analysis [29] of elastic nucleon scattering on different targets at energies up to 40 MeV, using the phenomenological nonlocal nucleon OP [30][31][32][33]. To validate the present nonlocal folding model of the nucleon OP, the OM results given by the nonlocal folded OP are also compared with those given by the global parametrization of the nonlocal nucleon OP suggested recently [31][32][33] using the analytical form of the Perey-Buck nonlocal form factor [30].…”

Rearrangement term in the nonlocal folding model of the nucleon optical potential

“…This Rmatrix method was recently extended [27,28] to include the Lagrange mesh and Gauss-Legendre quadrature integration that significantly simplify the numerical calculation. This method was tested in our recent OM analysis [29] of elastic nucleon scattering on different targets at energies up to 40 MeV, using the phenomenological nonlocal nucleon OP [30,31,32,33]. To validate the present nonlocal folding model of the nucleon OP, the OM results given by the nonlocal folded OP are also compared with those given by the global parametrization of the nonlocal nucleon OP suggested recently [31,32,33] using the analytical form of the Perey-Buck nonlocal form factor [30].…”