Speaker
Prof.
Stefan Frauendorf
(University Notre Dame)
Description
The short-range proton-neutron interaction favors the formation of p-n pairs with parallel or antiparallel spin. They may appear as three species: T=1,J=0 (“isovector pairing”), T=0,J=1 (“isoscalar pairing”), and T=0, J=2j (“spin-aligned”). In N≈Z nuclei, so far accessible, there is clear evidence for strong isovector pair correlations. Evidence for isoscalar pair correlations is elusive. The reason seems suppression by spin-orbit splitting. Weakening of spin-orbit splitting is predicted for the region N≈Z>50, which may lead to a rise of isoscalar pair correlations. Based on Shell Model calculations, the formation of a “condensate” of spin-aligned pairs was suggested. The nature of such spin-aligned coupling scheme, its coexistence with isovector pairing, and the limits of pair classification due to the finite nucleon number will be discussed.
Primary author
Prof.
Stefan Frauendorf
(University Notre Dame)
