Evidence for core-coupled states inY87from aY

Gamma-ray spectroscopy of87Y

“…The angular distribution results limit the J~ values for these levels to (7/2, 5/2) and 7/2-respectively. These levels may correspond to those observed at 1,609 and 1,991 keV in the 89y(p, t) reaction [6]. The 1,202.5keV transition, which was not seen in coincidence with any other ?…”

“…ray is thus probably El, and the 2,478.8 keV level a 13/2-. A (11/2, 13/2)-level has been observed at 2,486 keV in s9y(p, t) [6]; this is probably the level depopulated by the 888.2keV transition. Two other reasonably intense ?…”

“…The 1,202.5keV transition, which was not seen in coincidence with any other ? rays, probably depopulates the (5/2)-state observed at 1,205keV in s9y(p, t) [6] and 9~ c~) [-16] to the ground state. Since this 7 ray has an E2 angular distribution, the 1,202.5 keV state must then be 5/2 .…”

“…A comparison of the SSSr(p,t) S6Sr and 89y(p,t) 87y reactions [6] suggests that this description can be extended to the structure of 87y. A recent data compilation on sty [7] contains little information on y-ray spectroscopic results.…”

The mechanism of the (p, ?) reaction: Pick-up or knock-out?

“…In the figure the results we get assuming a single proton hole configuration for both states (broken lines) 3-are also shown. In the case of the ~ state a proton-hole core vibration component is certainly present as demonstrated by the rather intense population of this state in the SgY(p,t)sTY reaction [35,36].…”