Coincidence measurements of the reactions 12C(π+-,π+-)10B and 12C(π+-,π+-t)9B

We have measured the reactions 12C(π+-,π+-d)10B and 12C(π+-,π+-t)9B at an incident pion energy of 180 MeV, with two spectrometers in coincidence. The ratio sigma(π+,π+d)/sigma(π-,π-d) agrees with the iso-spin prediction of unity. There is evidence for quasi-elastic πd scattering. We obtain the surprising result that the ratio sigma(π,πd)/sigma(π,πp) for excitation energies less than 10 MeV, is equal to the ratio (dsigma/dΩ) (πd)/(dsigma/dΩ)(πp) for elastic (πd) and (πp) scattering at all the points we have measured. The ratio sigma(π-,π-t)/sigma(π+,π+t) is approximately one and there is no evidence for quasi-elastic πt scattering. (orig.)