Decay ofC10excited states above the2p+2αthreshold and the contribution from “democratic”

Abstract

The decay of 10 C excited states to the 2p + 2α exit channel has been studied using an E/A = 10.7 MeV 10 C beam inelastically scattered from a 9 Be target. Levels associated with two-proton decay to the ground state of 8 Be have been observed. These include states at 5.18 and 6.54 MeV which decay by sequential two-proton emission through the long-lived ground state of 9 B. In addition, states at 5.3 and 6.57 MeV were found in which there is no long-lived intermediate state between the two proton emissions. For the 6.57 MeV state, the two protons are preferably emitted on the same side of the decaying 10 C fragment.

Correlated two-proton decay fromC10

“…While angular momentum will generate correlations between successively emitted particles, θ pp rel distributions must remain symmetric about θ pp rel = 90 • [28]. The detector response (included in the simulations) induces only minor distortions [14]. The shapes of the E pp rel distributions are also markedly different for the two cases.…”

“…fragment [29]. Both the sequential (see [14] for this simulation) and the three-body phase space [see Figs. 4(a) [31].)…”

Density functional theory studies of cluster states in nuclei

“…The unique feature of this system is that the removal of any one of the four constituents results in an unbound three-body system. It can, therefore, be considered as a super-Borromean or fourth-order Brunnian nuclear system [60,61]. As the mirror nucleus of 10 Be, 10 C is expected to display a covalent 2-center chain configura- tion with a pair of protons as the covalent bond.…”

Breakup reaction study of the Brunnian nucleusC10

“…The removal of a proton from 10 C leads to 9 B, which is unbound to 8 Be + p decay by 185 keV. The removal of an α particle produces 6 Be.…”

“…The breakup kinematics were used to reconstruct the 10 C → 9 B +p, 9 B → 8 Be +p, 8 Be → α + α and 10 C → 6 Be +α, 6 Be → 5 Li +p, 5 Li → α + p decay paths. Proton emission was seen to be favored.…”