Observation of Isospin dependence on analyzing powers in proton inelastic scattering

Differential cross sections and analyzing powers in inelastic scattering of 65- and 50- MeV polarized protons exciting the 1+ states at 12.71 MeV (T=0) and 15.11 MeV (T=1) in C12 have been measured. There is a marked difference between the analyzing powers of the two states, which show an out-of-phase pattern in angular distribution. The exchange effect was found to contribute essentially to the isospin dependence from the results of distorted-wave Born-approximation calculations.