Neutron-proton pair transfer reactions and corresponding Weisskopf-type units

We introduce the concept of neutron-proton two-particle units (np-Weisskopf units) to be used in the analysis of the (3He,p) and (p,3He) reactions on nuclei along the N=Z line. These are presented for the conditions relevant to the (n,j,ℓ) orbits expected from 16O to 100Sn. As is the case of the Weisskopf units for electromagnetic transitions, the np-WU's will provide a simple, yet robust, measure of isoscalar and isovector np pairing collective effects.