Related papers: Two neutron decay from the $2_1^+$ state of $^6$He
We discuss a decay of unbound nuclei beyond the neutron drip-line using a three-body model with a core nucleus and two valence neutrons. We particularly discuss the role of dineutron correlation between the valence neutrons in the…
The particle unbound $^{26}$O nucleus is located outside the neutron drip line, and spontaneously decays by emitting two neutrons with a relatively long life time due to the centrifugal barrier. We study the decay of this nucleus with a…
We discuss the two-neutron emission decay of $^{26}$O nucleus from a viewpoint of dineutron correlations between the valence neutrons. We first discuss how the dineutron correlation is realized both in the coordinate space and in the…
Recently, the first example of two-neutron decay from the ground state of an unbound nucleus, $^{16}$Be, was seen. Three-body methods are ideal for exactly treating the degrees of freedom important for these decays. Using a basis expansion…
Neutron decay spectroscopy has become a successful tool to explore nuclear properties of nuclei with the largest neutron-to-proton ratios. Resonances in nuclei located beyond the neutron dripline are accessible by kinematic reconstruction…
A two-neutron unbound excited state of $^{24}$O was populated through a (d,d') reaction at 83.4 MeV/nucleon. A state at $E = 715 \pm 110$ (stat) $\pm 45 $ (sys) keV with a width of $\Gamma < 2$ MeV was observed above the two-neutron…
The linear-chain states of $^{16}$C and their decay modes are theoretically investigated by using the antisymmetrized molecular dynamics. It is found that the positive-parity linear-chain states have the $(3/2^-_\pi)^2(1/2^-_\sigma)^2$…
We investigate the dineutron in the $2^+_1$ state of $^6$He via analysis of its decay mode by using the complex scaling method. In this letter, we propose the cross section for the resonant state to distinguish the resonant contributions…
Particle-decaying states of the light nuclei $^{11,12}$N and $^{12}$O were studied using the invariant-mass method. The decay energies and intrinsic widths of a number of states were measured, and the momentum correlations of three-body…
The possibility for the excited nuclear states to decay by emission of the neutrino-antineutrino pair in direct competition with electromagnetic decay modes is commented upon.
We investigate the contribution of the $2^{+}_{2}$ resonance in $^6$He to observables via analysis of the $^6$He($p,p'$) reaction by using the continuum-discretized coupled channels method combined with the complex-scaling method. In this…
The structure of neutron-rich $\Lambda$ hypernucleus, $^7_{\Lambda}$He is studied within the framework of an $\alpha +\Lambda +n+n$ four-body cluster model. We predict second $3/2^+$ and $5/2^+$ states, corresponding to a $0s$ $\Lambda$…
The simultaneous beta decay of two neutrons in a nucleus without the emission of neutrinos (called neutrinoless double beta decay) is a lepton number violating process which is not allowed in the Standard Model of particle physics. More…
Enhancement, due to constructive interference through the many possible reaction channels, occurs in two-neutron transfer reactions from a bound system $A$ to a weakly-bound system ($A$+2), whenever the intermediate system is unbound and…
In this work we investigate the two-neutron decay of 13Li and of the excited states of 11Li populated via one-proton removal from 14Be and 12Be, respectively. A phenomenological model is used to describe the decay of 11Li and 13Li. While…
We describe a reaction mechanism which is consistent with all available experimental information of high energy three-body breakup processes. The dominating channels are removal of one of the three halo particles leaving the other two…
The weak binding and spatially extended neutron densities characteristic of drip-line nuclei give rise to a distinctive low-energy dipole response. The drip-line nucleus $^8$He is the most neutron-rich bound nucleus with a mass-to-charge…
We study the correlations between two neutrons in borromian nuclei $^{11}$Li and $^6$He by using a three-body model with a density-dependent contact two-body interaction. It is shown that the two neutrons show a compact bound feature at the…
The B(E2) value for the decay of the 2+_1 state in 16C to ground has been the subject of much discussion. Analyses assuming a simple model of two neutrons coupled to a 14C core of the available data, which extend over an order of…
The fluctuation properties of nuclear giant resonance spectra are studied in the presence of continuum decay. The subspace of quasi-bound states is specified by one-particle one-hole and two-particle two-hole excitations and the continuum…