Applying new tools to old problems—experimental studies of resonances in 12C

3rd International Workshop on "State of the Art in Nuclear Cluster Physics"

Kirsebom, O.S.^1 ; Fynbo, H.O.U.^1 ; Howard, A.M.^1 ; Laursen, K.L.^1

Department of Physics and Astronomy, Aarhus University, Aarhus C

8000, Denmark^1

关键词: A-particles;    Beam energies;    Combined energy;    Gamma transition;    Resonance spectrum;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/569/1/012013/pdf
DOI  :  10.1088/1742-6596/569/1/012013

来源: IOP

【 摘 要 】

We report preliminary results from an experimental study of the p +11B reaction at beam energies of 2.00 MeV, 2.63 MeV and 3.12 MeV, corresponding to three known 0+, 2+and 3-resonances in12C at excitation energies of 17.79 MeV, 18.38 MeV and 18.81 MeV. The resonances have small γ-decay branches to lower-lying resonances of the order of 10-6- 10-5. By detecting the three outgoing a particles in coincidence and measuring their momenta, we obtain complete kinematics information. From the combined energy of the α particles we determine the energy of the γ transition. In this way, we identify two previously observed transitions, (0+, 17.79) → (1+, 12.71) and (3-, 18.38) → (3-9.64), and one new transition, (2+, 18.81) → (1+, 12.71). The results demonstrate the usefulness of γ decay as a probe of the low-lying resonance spectrum of12C in the search for new broad (cluster) resonances.