Level structure of the double-shell closure system with Z=14 and N=20:^(34)Si

The level structure of the double-magic nucleus ^(34)Si(Z=14,N=20)was investigated by evaluating the available data.On the basis of experimental results from the beta-decay and fusion-evaporation reactions,we established the level scheme by assigning spin-parities up to 6_(1)^(+)at 6233 keV.The high energy positions of the excited states are consistent with the magicity at ^(34)Si,such as the 2_(2)^(+)state of the spherical ground band at 4.519 MeV and the 3^(-),4^(-),and 5^(-)states of the one-particle one-hole cross-shell states at approximately 4.5 MeV.This nucleus,for a long time,has attracted much attention because of,on one side,a proton bubble structure in the ground state and,on the other side,a deformation in the second 0^(+)state,0_(2)^(+).By a comparison of the constructed level scheme with the shell model calculations,we describe the emerging structures in the ground and second 0+states and the negative-parity 3^(-)states within the framework of the shell model context.We propose a deformed rotational band with the cascading 6_(2)^(+)−4_(1)^(+)−2_(1)^(+)transitions built on the 0_(2)^(+)state.

High spin states in ^(71)Ga

Excited states in the odd-A nucleus 71Ga have been studied via the ^(70)Zn(7Li,a2n)^(71)Ga fusion-evaporation reaction with incident beam energies of 30 and 35 MeV.The level scheme is established up to spin I^(n)=(29/2^(+))and an excitation energy-6.6 MeV.A previously known sequence built on the 9/2^(+) state is extended as a novel rotational band originating from the v(8^(2)_(9/2)alignment.Furthermore,a negative-parity sequence Is also reported.The observed energy levels of Ga have been interpreted in the framework of the nuclear shell model(SM).