Different Methods for Pion-nucleus Optical Potential

Elastic and inelastic cross-sections for pion scattering on ¹²C at pion kinetic energy ranging from 50 to 260 MeV are computed using three independent methods of π^± -nucleus optical potential, the 3α-particle model of the nucleus, the equivalent local Kisslinger potential and the Laplacian one. Reasonable fits to the measured values are obtained for ¹²C without adjusting free parameters. The ability of these methods to account for elastic, inelastic, total and reaction cross-section data are somewhat similar. The Kisslinger-based local potential is the more suitable for describing the elastic and inelastic cross-sections of π^±-nucleus scattering. It seems that the 3α-particle model of ¹²C is not useful in the description of pion scattering on ¹²C at least in the Δ-resonance region.