Identification of rotating and vibrating tetrahedrons in the heavy nucleus 208Pb
Abstract.Ten known states in the heavy nucleus 208Pb at $2.6 < E_{x} < 7.9$2.6<Ex<7.9 MeV are described by rotating and vibrating tetrahedrons. The $ 3^{-}$3- and $ 4^{+}$4+ yrast states are the first members of the rotational band. A $ 2^{\pm}$2± doublet state with the $ 2^{+}$2+ yrast state as one member and the newly recognized $ 2^{-}$2- yrast state as the other member, the $ 1^{-}$1- yrast state, and the third $ 0^{+}$0+ state are the heads of the three elementary tetrahedral rotating and vibrating bands. The newly recognized state at $ E_{x} = 4142$Ex=4142 keV was assigned spin 2 in 1975 and is suggested to have negative parity by the absent 208Pb $(\alpha, \alpha')$(α,α) excitation. Four more states at $5.7< E_{x}< 7.9$5.7<Ex<7.9 MeV are identified as the next members of the three elementary tetrahedral rotating and vibrating bands. The ambiguous spin assignment to the state at $E_{x}= 7020$Ex=7020 keV is settled with $ 3^{-}$3-, the state at $ E_{x} = 7137$Ex=7137 keV is assigned $ 4^{-}$4-.