Two-proton transfer near Z = 40

On the (3He,n) reaction in theA ? 100 region

“…The fact that only pure configurations were considered allows the factorization of the calculated cross sections into a nuclear reaction part and a nuclear structure part, the latter being contained in the enhancement factor e. The shape of the calculated angular distributions for L= 0 transitions, and in particular its strong forward peak, is insensitive, at least within reasonable limits, to the following choices: (i) the optical model parameters; (ii) the Woods-Saxon potential for the transferred protons; (iii) the configurations of the transferred pair. Furthermore, it agrees with the shape of the experimental angular distributions, as already shown in [6][7][8] and further confirmed in the present work. However, the absolute values of the calculated angular distributions, and hence the enhancement factors e, are very sensitive to these choices, and in particular to the adopted configurations.…”

“…The experimental 0 ~ differential cross sections for the A(3He, n)B reactions [6][7][8] have been compared to the results of DWBA calculations, carried out using the programme DWUCK4 [9], in order to obtain the so-called enhancement factors e, defined in [6][7][8], and given by:…”

“…Simple analytical expressions can be obtained in the two models for the relative intensities of the L=0 transfers between the 0 § ground states of even-even nuclei [4,5]. Extensive experimental data are available on the (3He, n) two-proton transfer reaction in the A~100 region [6][7][8], and in particular on the cross sections at 0 ~ for the L=0 transfers between the ground states of the even-even Sr, Zr, Mo, Ru, Pd, Cd and Sn isotopes I- 6,7], and between the lowest 1/2-levels in the odd-Z Ag and In isotopes [8]. They were obtained at the same laboratory, using the same 3He energy (25.4MeV), and under the same experimental conditions.…”

Neutron pair correlations inA=100nuclei involved in neutrinoless double-βdecay

“…Some data exist on the proton-pair transfer reaction ( 3 He, n) on stable A ∼ 100 targets [28]. Within the experimental sensitivity, no excited 0 + states were observed in reactions on 100 Mo and 100 Ru, and ground-state reaction cross sections display the same similarity.…”

Proton pair correlations and the neutrinoless double-βdecay of76Ge

“…• cross sections for populating the ground states in 60,62,64,66 Zn [15] and 90 Zr [21] are shown in Fig. 4, together with data points for 76,78 Se from the present work.…”