Elastic and inelastic scattering of π+ and π- on 12C at 995 MeV/c

pi(+) and pi(-) elastic and inelastic scattering to the 2(1)(+)(4.44 MeV) state on C-12 at 995 MeV/c were measured over an angular range for elastic-scattering from 5.4(degrees) to 28.2(degrees) and for inelastic scattering from 15.2(degrees) to 22.8(degrees). Both of the elastic-scattering data sets were well reproduced by first-order factorized momentum-space optical potential calculations with free pi-N elementary amplitudes and three different ground state densities, which were deduced from the charge density and microscopic model calculations, the cluster model and the shell model. We also extracted sigma(tot),sigma(el), and sigma(R) phenomenologically and compared them with a Fermi averaging model. The inelastic cross sections of pi(+)-C-12 and pi(-)-C-12 were compared with the DWIA calculations, one using the transition density(0(+)-> 2(1)(+)) deduced by the cluster model and the other using the transition density deduced by the shell model.