Differential cross section and polarization for 2.63 MeV neutrons scattered from 12C

The differential cross section and polarization of 2.63 MeV neutrons scattered from ¹²C have been measured at eight angles between 17° and 118° in the laboratory system. By simultaneously fitting the cross section and polarization data, a set of scattering phase shifts was obtained. The values of the resulting d-wave phase shifts were larger than those of other existing sets of phase shifts in the energy region. A subsequent R-function analysis, reflecting these larger d-wave phase shifts, gave excellent fits to other experimental data below 3 MeV neutron energy region. The influence of narrow states at 7.50 and 7.55 MeV excitation energy in ¹³C is discussed.