SPIN DETERMINATION OF VALENCE AND INNER HOLE STATES VIA THE PB-208((D)OVER-RIGHT-ARROW,T)PB-207 REACTION AT ED=200 MEV

Highly excited neutron hole states in Pb-207 have been studied via the (d, over arrow pointing right, t) reaction at E(d) = 200 MeV using for the first time a polarized beam, with both vector and tensor components. The determination of overlapping neutron hole response functions takes advantage of the strong characteristic features of j- = l - 1/2 versus j+ = l + 1/2 level analyzing powers and of the good distorted wave Born approximation (DWBA) description of the reaction. A least-squares fit analysis of the sigma, A(y), and A(yy) angular distributions has allowed a determination of the high j transition spectroscopic factors contributing to the excitation energy bins up to E(x) = 14.5 MeV. The results are compared in details with those relying only on l identification, previously obtained in the 1i13/2 and 1h9/2 valence state fragmentation up to E(x) = 6.7 MeV and on the 1h11/2 strength up to approximately 10 MeV. Several previous conclusions are unambiguously confirmed, in particular, the attribution of the bump around E(x) = 8.2 MeV to the 1h11/2 strength. In addition, the present experiment settles the attributions of several j - versus j + valence groups and indicates that the 1h9/2 strength is spread up to approximately 10. 8 MeV. The analysis performed up to E(x) = 14.5 MeV gives the first determination of the 1h 11/2 strength beyond the bump, and a first reliable evidence for the 1g7/2 strength, with the maximum around E(x) = 11MeV. Approximately 85% of these inner hole state sum rules are exhausted in the studied excitation energy range. The spin-orbit splitting of 1h orbitals in Pb-208 deduced from the strength centroids is 5.2 MeV. The experimental strength distributions and the integral characteristics of the 1i13/2, 1h9/2, 1h11/2, and 1g7/2 hole states are compared with the results from different theoretical approaches, i.e., microscopic calculations of the fragmentation and phenomenological calculations of spectral functions in a modified mean field. The comparison reports on the sharing of the valence strengths between each quasihole level and the other fragments, characterized by their centroids and widths, and on the shape of the inner hole strength distributions, the centroids and spreading widths.