Experimental determination of the Jπ components of the spin-dipole resonance in 12B

The inclusive C12(d→,He2) and exclusive C12(d→,He2+n) reactions have been studied with a beam energy of 171 MeV and scattering angles for the (d,He2) reaction θ=0° and 3°. The studies focused on the separation of the isovector spin-dipole resonance (IVSGDR) into its components by measuring tensor-analysing powers and observing the direct neutron decay to the low-lying proton-hole states in 11B. Merging the information obtained from both measurements resulted in the first-time verification of model-independent predictions of tensor-analysing powers at extreme forward angles and the experimental decomposition of the IVSGDR into its Jπ components. The experimental results are in reasonable agreement with theoretical estimates based on shell-model calculations.