Evolution of quadrupole collectivity in Te isotopes

AbstraktAbstract

Mean lifetimes of the low-lying positive-parity yrast states up to J pi = 6+ in 116Te were measured with the recoil distance Doppler shift method, and the corresponding B(E2) values were deduced. Using our values for 116Te and the most recent measured transition strengths for the other isotopes in this region, we show that the B(E2) values, especially those of the 2+ -> 0+ transition, show a smooth evolution of quadrupole collectivity, with only a slight asymmetric behavior across the middle of the shell, in contrast to the one found in Sn isotopes. The transition strengths of even-even Te isotopes are then compared with systematic theoretical calculations within the shell model using the realistic pairing plus multipole terms with monopole interaction and the largescale shell-model configuration-interaction approach with a realistic interaction, while the projected shell model is applied to calculate only the structure of 116Te. The latter model gives a very good description of the individual B(E2) values in 116Te, while the first two models predict a stronger asymmetric behavior across the middle of the shell than the one observed experimentally.

Mean lifetimes of the low-lying positive-parity yrast states up to J pi = 6+ in 116Te were measured with the recoil distance Doppler shift method, and the corresponding B(E2) values were deduced. Using our values for 116Te and the most recent measured transition strengths for the other isotopes in this region, we show that the B(E2) values, especially those of the 2+ -> 0+ transition, show a smooth evolution of quadrupole collectivity, with only a slight asymmetric behavior across the middle of the shell, in contrast to the one found in Sn isotopes. The transition strengths of even-even Te isotopes are then compared with systematic theoretical calculations within the shell model using the realistic pairing plus multipole terms with monopole interaction and the largescale shell-model configuration-interaction approach with a realistic interaction, while the projected shell model is applied to calculate only the structure of 116Te. The latter model gives a very good description of the individual B(E2) values in 116Te, while the first two models predict a stronger asymmetric behavior across the middle of the shell than the one observed experimentally.