Molecular states in neutron-rich beryllium isotopes

A new experimental study of the12Be cluster structure

“…We compared our results with the generalized two-center cluster Model(GTCM) calculation by Ito [21] in Fig 4, together with resonances reported by Freer et al [15], Saito et.al [22] and Charity et al [16]. Good agreements with the GTCM calculation and previously reported data was achieved, although an overall shift of about 1.5MeV from the experimental results to the GTCM calculation was observed for the 6 He- 6 He band.…”

“…The reconstructed 12 Be excitation energy spectra(not corrected for the detection efficiency) for 6 He+ 6 He and 4 He+ 8 He are displayed in Fig 3(a) and (b), respectively. [15,16,22] and the results of this work, while the GTCM calculation is from [21].…”

Helium-helium clustering states inBe12

“…Unexpectedly, most of the resonances, reported by Freer et al, could not be reproduced in this work, although higher statistics were accumulated [34]. Meanwhile, hints of MR states in 12 Be were also reported in some other measurements [35][36][37]. It is worth noting that the lowlying 0 + and 2 + MR states were missed in the experiments of Freer et al and Charity et al, owing to the noncoverage of the detectors around zero degrees, resulting in a very low detection efficiency at small decay energies.…”

“…Excited states at ∼10 MeV were also reported from a proton inelastic scattering experiment by Korsheninnikov et al [35] and from a transfer experiment by Bohlen et al as well [37]. There is also a hint of a wide peak at around 10 MeV in the E x spectrum measured by Saito et al [36], although beneath it is seen a high background, possibly due to the high incident energy (see discussions in Subsec. B below).…”

Investigation of Cluster States in $^{13}$B Using the $^{9}$Li--$\alpha $ Resonant Elastic Scattering

“…As far as experimental observations of exotic clustering are concerned, the literature is not so rich, mainly due to the difficulty of performing experiments with the typically low currents of radioactive beams, very often needed for this type of researches. One of the experimentally most studied system is the 12 Be nucleus for which very different conclusions on the existence of a rotational band associated with an exotic 6 He-6 He cluster configuration have been drawn [3][4][5]. As far as boron is concerned, calculations performed in the framework of Antisymmetrized Molecular Dynamics (AMD) [6] describe some of the states of the very neutron-rich isotopes in terms of two clusters of He-Li type.…”