Compound and quasicompound states in low-energy scattering of nucleons from C12

A multichannel algebraic scattering theory has been used to study the properties of nucleon scattering from C12 and of the subthreshold compound nuclear states. The theory accounts for properties in the compound nuclei to â10 MeV. All compound and quasicompound resonances observed in total cross-section data are matched, and, on seeking solutions of the method at negative energies, all subthreshold states in C13 and N13 are predicted with the correct spin-parities and with reasonable values for their energies. A collective-model prescription has been used to define the initiating nucleon-C12 interactions and, via use of orthogonalizing pseudopotentials, account is made of the Pauli principle. Information is extracted on the underlying structure of each state in the compound systems by investigating the zero-deformation limit of the results.