Complete correlation studies of two-proton decays: 6Be and 45Fe

Abstract

The complete three-body correlation pictures are experimentally reconstructed for the two-proton decays of the 6 Be and 45 Fe ground states. We are able to see qualitative similarities and differences between these decays. They demonstrate very good agreement with the predictions of a theoretical three-body cluster model. Validity of the theoretical methods for treatment of the three-body Coulombic decays of this class is thus established by the broad range of lifetimes and nuclear masses spanned by these cases. Implementations for decay dynamics and nuclear structure of 2p emitters are discussed.

Role of diproton correlation in two-proton-emission decay of theBe6nucleus

“…Intuitively, from the uncertainty principle, this would correspond to a large opening angle in the momentum space. Indeed, such component has been experimentally observed to be dominant for the 2p-decay of 6 Be [40,41]. It would be an interesting future work to carry out the Fourier transformation of the decay state and compare our calculations with the experimental data.…”

“…It has been considered now that the actual 2p-decays are often much more complicated than the simple diproton decays which Goldansky originally proposed [39][40][41][42][43][44][45][46][47]. Moreover, it has not been completely clarified whether the diproton correlation can be actually probed by observing 2p-decays.…”

“…We here apply this method to a realistic system, that is, the ground state of the 6 Be nucleus, by assuming the three-body structure of α + p + p. The 6 Be nucleus is the lightest 2p-emitter, where the 2p-emission decay from its ground state has been experimentally studied in Refs. [39][40][41][42]. The experimental Q-value of the 2p-emission is 1.37 MeV [63,64], while the 5 Li nucleus is unbound by 1.96(5) MeV from the threshold of α + p [63], as shown in Fig.…”

Analysis of the effect of core structure upon dineutron correlation using antisymmetrized molecular dynamics

“…These studies clarify that the strength of dineutron correlation reflected in the dineutron size changes significantly depending on circumstances such as nuclear density and potential from the core. In addition, the dineutron and diproton correlations have been intensively discussed via 2n and 2p emissions from the unbound nuclei in connection with recent experiments [18][19][20][21][22][23][24][25][26][27][28][29].…”

Two-proton decay from the isobaric analog state inB8

“…This beam impinged on a 9 Be production target and a secondary beam of 9 C (E/A = 68 MeV) was selected using the A1900 fragment separator. The secondary beam had an intensity of 1.2 x 10 5 pps and a 9 C purity of 52% with the main contaminant being 6 Li.…”