Experimental investigation of a linear-chain structure in the nucleus 14C

Abstract

It is a well-known fact that a cluster of nucleons can be formed in the interior of an atomic nucleus, and such clusters may occupy molecular-like orbitals, showing characteristics similar to normal molecules consisting of atoms. Chemical molecules having a linear alignment are commonly seen in nature, such as carbon dioxide. A similar linear alignment of the nuclear clusters, referred to as linear-chain cluster state (LCCS), has been studied since the 1950s, however, up to now there is no clear experimental evidence demonstrating the existence of such a state. Recently, it was proposed that an excess of neutrons may offer just such a stabilizing mechanism, revitalizing interest in the nuclear LCCS, specifically with predictions for their emergence in neutron-rich carbon isotopes. Here we present the experimental observation of α-cluster states in the radioactive 14C nucleus. Using the 10Be+α resonant scattering method with a radioactive beam, we observed a series of levels which completely agree with theoretically predicted levels having an explicit linear-chain cluster configuration. We regard this as the first strong indication of the linear-chain clustered nucleus.

15 pages, 3 figures

References in corpus (2)

• Cluster structures of excited states in ${}^{14}$C
• Approximation of reduced width amplitude and application to cluster decay width

Cited by in corpus (9)

• Positive-parity linear-chain molecular band in ${}^{16}$C
• Dynamics of the linear-chain alpha cluster in microscopic time-dependent relativistic density functional theory
• Cluster structures and monopole transitions of ${}^{14}$C
• Shape of 13C studied by the real-time evolution method
• First observation of the $\beta$3$\alpha$p decay of ${}^{13}\mathrm{O}$ via $\beta$-delayed charged-particle spectroscopy
• A variety of clustering in ${}^{18}$O
• Drastic change in inelastic scattering depending on the development of dineutron correlation in ${}^{10}$Be
• The lowest excited states of 14C and 14O nuclei within a five-cluster model
• 4$\alpha$ linear-chain state produced by ${}^9$Be+${}^9$Be collision