1(-) and 2(+) discrete states in Zr-90 populated via the (O-17, O-17 'gamma) reaction
2015 (English)In: Physical Review C. Nuclear Physics, ISSN 0556-2813, E-ISSN 1089-490X, Vol. 91, no 2, 024323Article in journal (Refereed) Published
2(+) and 1(-) states in Zr-90 were populated via the (O-17, O-17 'gamma) reaction at 340 MeV. The gamma decay was measured with high resolution using the AGATA (advanced gamma tracking array demonstrator array). Differential cross sections were obtained at few different angles for the scattered particle. The results of the elastic scattering and inelastic excitation of 2(+), 3(,)(-) and 1(-) states are compared with distorted-wave Born approximation (DWBA) calculations, using both the standard collective form factor and a form factor obtained by folding microscopically calculated transition densities. This allowed to extract the isoscalar component of the 1(-) state at 6.424 MeV. The comparison of the present (17O, 17O 'gamma) data with existing (gamma,gamma') and (p, p') data in the corresponding region of the gamma continuum (6-11 MeV), characterized by a large E1 component, shows completely different behaviors of the cross section as a function of the nuclear excitation energy. The comparison of the data with DWBA calculations suggests a decrease of the isoscalar strength in the cross section with increasing excitation energy.
Place, publisher, year, edition, pages
2015. Vol. 91, no 2, 024323
IdentifiersURN: urn:nbn:se:kth:diva-163473DOI: 10.1103/PhysRevC.91.024323ISI: 000350104800002ScopusID: 2-s2.0-84923872912OAI: oai:DiVA.org:kth-163473DiVA: diva2:800946
QC 201504082015-04-082015-04-072015-04-08Bibliographically approved