Popis: |
The cross sections for the reactions 12C(γ,π+)12B and 12C(γ,π−)12N to various states of the final nucleus have been measured at a pion energy around 29 MeV for electron energies from 187 to 193 MeV, and at a pion energy around 17 MeV with electron energies from 174 to 181 MeV, and at a pion angle 90° with respect to the incident photon beam. The observed states in 12B and 12N are the analogues of T = 1 states in 12C which are excited by inelastic electron scattering1,2. Furthermore, the (γ,π) one-body operator tends to strongly excite spin-flip components of the transitions to these states. |