Comparative analysis of the pion-nucleus scattering within the microscopic Folding and the local Kisslinger type potentials

Abstract

Abstract. Elastic scattering cross sections are calculated and compared to the data of π ± + 28 Si and 40 Ca at energies 130, 180, and 230 MeV by using the both microscopic optical potentials (OP), the high-energy folding and the local Kisslinger type potentials. In the folding OP, we use the known nuclear density distributions while parameters of the elementary πN-scattering amplitude are fitted to the data with the aim to estimate the inmedium effect on pions scattered on bound nucleons. As to the local modified Kisslinger OP its parameters are known from the earlier studies. The cross sections for both OPs are calculated by solving the Klein-Gordon wave equation, and thus the relativistic and distortion effects on the process are accounted for exactly. A fairly well agreement with experimental data was obtained and the decisive role of a surface region of potentials was established where both OPs occur in close coincidence.

Analysis of the pion-nucleus scattering within the folding and the Kisslinger type potentials

“…The solid red curves are the calculated cross sections for the folding OP (6) where one applies the SF-density distribution function of point-like nucleons to the nucleus 28 Si with the radius and diffuseness parameters R c = 3.134 fm and a c = 0.477 fm (see Refs. [21,22]). The dashed blue curves correspond to the cross sections calculated by using the Kisslinger type microscopic OP, where the nuclear density distribution has the same form (7) but with the parameters R = 3.14 fm and a = 0.537 fm from Ref.…”

“…[24]). For this nucleus, when calculating folding OPs we use the point-like nucleon fermi density parameters R c = 3.593 fm, a c = 0.493 fm (solid red curves) [21], and for the Kisslinger OPs (dashed blue curves), the parameters R = 3.53 fm and a = 0.562 fm for distribution of realistic nuclear nucleons [22] .…”