We investigate the possibility of the existence of the exotic torus configuration in the high-spin excited states of ${}^{40}\mathrm{Ca}$. We here consider the spin alignments about the symmetry axis. To this end, we use a three-dimensional cranked Skyrme Hartree-Fock method and search for stable single-particle configurations. We find one stable state with the torus configuration at the total angular momentum $J=60\hslash$ and an excitation energy of about 170 MeV in all calculations using various Skyrme interactions. The total angular momentum $J=60\hslash$ consists of aligned 12 nucleons with the orbital angular momenta $\Lambda =+4$, $+5$, and $+6$ for spin-up or -down neutrons and protons. The obtained results strongly suggest that a macroscopic amount of circulating current breaking the time-reversal symmetry emerges in the high-spin excited state of ${}^{40}\mathrm{Ca}$.

• Received 26 July 2012

DOI:https://doi.org/10.1103/PhysRevLett.109.232503