A DWBA analysis of the reaction and implications for a 87Rb solar neutrino detector

An experimental view on shape coexistence in nuclei

“…The irregular pattern of kinematic moments of inertia at lower spin can be related to the crossing and mixing of the two configurations characterised by different deformations. Interestingly, the moments of inertia obtained for 190 Po follow this pattern very closely, while those for 192,194 Po, which evolve smoothly, are considerably lower. In the absence of data on non-yrast states in these isotopes, it may still be concluded from this observation that a weakly deformed configuration forms the yrast states for N ≥ 108 (i.e., in 192 Po and the heavier Po isotopes), and in 190 Po (N = 106) the prolate-deformed intruder states of spin 2 + and above have descended in energy below their weakly deformed counterparts.…”

“…Similar conclusions can be drawn from a recent 80 Ge(d, p) 81 Ge study [187], which deduced strong 3s 1/2 and 2d 5/2 components in 679-keV 1/2 + and 711-keV 5/2 + states, respectively, thus linking them to neutron promotion across the N = 50 shell gap. Low-lying states of a 2h − 1p intruder configuration were also identified in N = 49 isotones 83 Se [188], 85 Kr [189], and 87 Sr [190] via (d, p) transfer reactions.…”

“…The observation of the fine structure of the α decay of 190 Po allowed identification of two 0 + states in 186 Pb [498]. On the basis of α-decay hindrance factors, the 532(21) keV 0 + 2 state was associated with a mainly π(2p − 2h) configuration.…”

“…Experimental information for 190 Pb is more detailed, but the low-energy spectrum is dominated by the weakly deformed structures, including microsecond 11 − and 12 + isomers assigned to different configurations, although a candidate prolate band was proposed [510]. An excited 0 + state was identified in α-decay studies [511] at 658 keV, but no γ-ray transitions feeding this state are known.…”

“…The microscopic configurations of the two coexisting structures in light Hg nuclei were inferred via systematic α-decay studies [477,478]. In general, the α decays of the 186,188,190 Pb isotopes to the 0 + 2 states in 182,184,186 Hg are strongly hindered compared to the decays proceeding directly to the ground state, and the observed hindrance factors are of similar magnitude (≈10-20) for all three isotopes. This was interpreted as resulting from the normal-order configuration of the ground states of Pb and Hg nuclei and an intruder nature of the 0 + 2 states in 182,184,186 Hg: the population of an intruder state in the α decay of a normal-configuration state involves the removal of a proton pair from an orbital below the Z = 82 gap and the promotion of a proton pair across this gap.…”