Lifetime measurement of the first excited $2^{+}$ state in ${}^{112}\mathrm{Te}$

The lifetime of the $2^{+}\to 0_{\mathrm{g}.\mathrm{s}.}^{+}$ transition in the neutron-deficicient nucleus ${}^{112}\mathrm{Te}$ has been measured for the first time using the DPUNS plunger and the recoil distance Doppler shift technique. The deduced value for the reduced transition probability is $B(E2:0_{\mathrm{g}.\mathrm{s}.}^{+}\to 2^{+})=0.46\pm 0.04e^2{\mathrm{b}}^2$, indicating that there is no unexpected enhancement of the $B(E2:0_{\mathrm{g}.\mathrm{s}.}^{+}\to 2^{+})$ values in Te isotopes below the midshell. The result is compared to and discussed in the framework of large-scale shell-model calculations.

Figure 1

Spectra of the $2^{+}\to 0^{+}$ transition in ${}^{112}\mathrm{Te}$ obtained by gating on the 787-keV $\left(4^{+}\to 2^{+}\right)$ transition for six plunger distances. The dashed (blue) and continuous (red) lines correspond to the shifted and degraded components at 689 and 696 keV, respectively.

Figure 2

The upper two panels show the intensities of the degraded (a) and shifted (b) components of the $\gamma$ rays depopulating the $2^{+}$ state, as a function of the distance. The lifetime value obtained in the present measurement for the sensitive region is shown in panel (c).

Figure 3

Comparison of the theoretical and experimental $B(E2;0_{\mathrm{g}.\mathrm{s}.}^{+}\to 2^{+})$ values for the Te isotopic chain. The solid line corresponds to the calculation in which the full model space $(g_{7/2},d_{5/2},d_{3/2},s_{1/2}$, and $h_{11/2})$ has been considered for all nuclei except ${}^{116-120}\mathrm{Te}$ (marked by small solid squares) while the dashed line represents the calculation in the smaller space, see the main text for more details.