First Measurement of the Giant Monopole and Quadrupole Resonances in a Short-Lived Nucleus: 56Ni

C. Monrozeau (1) , E. Khan (1) , Y. Blumenfeld (1) , C. E. Demonchy (2, 3) , W. Mittig (4) , P. Roussel-Chomaz (4) , D. Beaumel (1) , M. Caamaño (5) , D. Cortina-Gil (5) , J. P. Ebran (1) , N. Frascaria (1) , U. Garg (6) , M. Gélin (4) , A. Gillibert (7) , D. Gupta (1) , N. Keeley (7) , F. Maréchal (1) , A. Obertelli (7) , J.-A. Scarpaci (1)

1 IPNO - Institut de Physique Nucléaire d'Orsay
2 Department of Physics, Olivier Lodge laboratory
3 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan
4 GANIL - Grand Accélérateur National d'Ions Lourds
5 USC - Universidade de Santiago de Compostela [Spain]
6 Physics Department
7 DAPNIA - Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée

The isoscalar giant monopole resonance (GMR) and giant quadrupole resonance (GQR) have been measured in the Ni56 unstable nucleus by inducing the Ni56(d,d′) reaction at 50A  MeV in the Maya active target at the GANIL facility. The GMR and GQR centroids are measured at 19.3±0.5  MeV and 16.2±0.5  MeV, respectively. The corresponding angular distributions are extracted from 3° to 7°. A multipole decomposition analysis using distorted wave Born approximation with random phase approximation transition densities shows that both the GMR and the GQR exhaust a large fraction of the energy-weighted sum rule. The demonstration of this new method opens a broad range of giant resonance studies at intermediate-energy radioactive beam facilities.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

C. Monrozeau, E. Khan, Y. Blumenfeld, C. E. Demonchy, W. Mittig, et al.. First Measurement of the Giant Monopole and Quadrupole Resonances in a Short-Lived Nucleus: 56Ni. Physical Review Letters, 2008, 100, pp.042501. ⟨10.1103/PhysRevLett.100.042501⟩. ⟨in2p3-00238507⟩