Evidence for Triangular D_3h Symmetry in 12C

Abstract

We report a measurement of a new high spin Jp = 5- state at 22.4(0.2) MeV in 12C which fits very well to the predicted (ground state) rotational band of an oblate equilateral triangular spinning top with a D_3h symmetry characterized by the sequence 0+, 2+, 3-, 4+/-, 5- with almost degenerate 4+ and 4- (parity doublet) states. Such a D_3h symmetry was observed in triatomic molecules and it is observed here for the first time in nuclear physics. We discuss a classification of other rotation-vibration bands in 12C such as the (0+) Hoyle band and the (1-) bending mode band and suggest measurements in search of the predicted ("missing") states that may shed new light on clustering in 12C and light nuclei. In particular the observation (or non-observation) of the predicted ("missing") states in the Hoyle band will allow us to conclude the geometrical arrangement of the three alpha-particle composing the Hoyle state at 7.654 MeV in 12C.

Accepted for Publication in the Physical Review Letters

References in corpus (3)

• Structure and rotations of the Hoyle state
• Evidence for Triangular D_3h Symmetry in 12C
• Evidence for tetrahedral symmetry in 16O

Cited by in corpus (29)

• Evidence for Triangular D_3h Symmetry in 12C
• Giant Dipole Resonance as a Fingerprint of $\alpha$ Clustering Configurations in ${}^{12}$C and ${}^{16}$O
• Symmetry-guided large-scale shell-model theory
• Status of Alpha-Particle Condensate Structure of the Hoyle State
• Density Functional Theory studies of cluster states in nuclei
• Alpha particle clusters and their condensation in nuclear systems
• States of Carbon-12 in the Skyrme Model
• Origin of Low-Lying Enhanced E1 Strength in Rare-Earth Nuclei
• Alpha clusters and collective flow in ultra-relativistic carbon - heavy nucleus collisions
• Evidence for Triangular D'(3h) Symmetry in 13C
• The container picture with two-alpha correlation for the ground state of ${}^{12}$C
• A stringent upper limit on the direct 3$\alpha$ decay of the Hoyle State in ${}^{12}$C
• Monopole excitation of the Hoyle state and linear-chain state in 12C
• Reorientation-effect measurement of the first 2${}^{+}$ state in ${}^{12}$C: confirmation of oblate deformation
• Clustering structure effect on Hanbury-Brown-Twiss correlation in ${}^{12}$C + ${}^{197}$Au collisions at 200 GeV}
• Two-proton momentum correlation from photondisintegration of $\alpha$-clustering light nuclei in the quasi-deuteron region
• Nonlocalized motion in two-dimensional container of $\alpha$ particles in $3^{-}$ and $4^{-}$ states of ${}^{12}$C
• Transition densities and form factors in the triangular $\alpha$-cluster model of ${}^{12}$C with application to ${}^{12}$C+$\alpha$ scattering
• Three-body bremsstrahlung and the rotational character of the 12C-spectrum
• ${}^8$He and ${}^9$Li cluster structures in light nuclei
• 16O within the Semimicroscopic Algebraic Cluster Model and the importance of the Pauli Exclusion Principle
• The Hoyle state and its relatives
• Effect of Coulomb energy on Skyrmions
• Higher-rank discrete symmetries in the IBM. I Octahedral shapes: general Hamiltonian
• Unbound states in ${}^{12}$C populated by $\gamma$-decay of the $(J^{\pi },T)=(2^{+},1)$ 16.11 MeV state
• Borromean structures in medium-heavy nuclei
• Electromagnetic transitions in the algebraic cluster model
• Algebraic cluster models calculations for shape phase transitions of boson-fermion systems
• An overview of the scientific contribution of Andrea Vitturi to Nuclear Physics (being an account of the recent TNP19 meeting held in Padova)