Pygmy dipole resonance in Sn-124 populated by inelastic scattering of O-17

• Published in: Physics letters. B Vol. 738; no. 738; pp. 519 - 523
• Main Authors: Pellegri, L., Bracco, A., Crespi, F.C.L., Leoni, S., Camera, F., Lanza, E.G., Kmiecik, M., Maj, A., Avigo, R., Benzoni, G., Blasi, N., Boiano, C., Bottoni, S., Brambilla, S., Ceruti, S., Giaz, A., Million, B., Morales, Ai, Nicolini, R., Vandone, V., Wieland, O., Bazzacco, D., Bednarczyk, P., Bellato, M., Birkenbach, B., Bortolato, D., Cederwall, B., Charles, L., Ciemala, M., de Angelis, G., Desesquelles, P., Eberth, J., Farnea, E., Gadea, A., Gernhauser, R., Gorgen, A., Gottardo, A., Grebosz, J., Hess, H., Isocrate, R., Jolie, J., Judson, D., Jungclaus, A., Karkour, N., Krzysiek, M., Litvinova, E., Lunardi, S., Mazurek, K., Mengoni, D., Michelagnoli, C., Menegazzo, R., Molini, P., Napoli, D.R., Pullia, A., Quintana, B., Recchia, F., Reiter, P., Salsac, M.D., Siebeck, B., Siem, S., Simpson, J., Soderstrom, P.A., Stezowski, O., Theisen, C., Ur, C., Dobon, J.J.V., Zieblinski, M.
• Format: Journal Article
• Language: English
• Published: Elsevier 10.11.2014
• Subjects: Isospin character; Low-lying electric dipole excitations Sn-124; Nuclear Experiment; Physics; Isospin character; STRENGTH; NUCLEI; ARRAY; Low-lying electric dipole excitations Sn-124
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2014.08.029

The gamma decay from the high-lying states of Sn-124 was measured using the inelastic scattering of O-17 at 340 MeV. The emitted gamma rays were detected with high resolution with the AGATA demonstrator array and the scattered ions were detected in two segmented Delta E-E silicon telescopes. The angular distribution was measured both for the gamma rays and the scattered O-17 ions. An accumulation of E1 strength below the particle threshold was found and compared with previous data obtained with (gamma,gamma') and (alpha,alpha'gamma) reactions. The present results of elastic scattering, and excitation of E2 and E1 states were analysed using the DWBA approach. From this comprehensive description the isoscalar component of the 1-excited states was extracted. The obtained values are based on the comparison of the data with DWBA calculations including a form factor deduced using a microscopic transition density.