Predictions for the α-decay chains of $Z=120$ superheavy nuclei in the range $272\le A\le 319$

The predictions on the $\alpha$-decay chains of the isotopes of the superheavy nuclei with $Z=120$ in the range $272\le A\le 319$ have been done within the Coulomb and proximity potential model for deformed nuclei. A comparison of our calculated $\alpha$ half-lives with the values computed using the Viola-Seaborg [J. Inorg. Nucl. Chem. 28, 741 (1966)] systematic, the universal curve of Poenaru et al. [Phys. Rev. C 74, 014312 (2006)], and the analytical formulas of Royer [J. Phys. G: Nucl. Part. Phys. 26, 1149 (2000)] show good agreement with each other. An extensive study on the spontaneous fission half-lives of all the isotopes under study has been performed to identify the mode of decay of these isotopes. The study reveals that the $\alpha$-decay half-lives and the mode of decay of the isotopes of ${}^{298,299}120$, which are evaluated by using our formalisms, agree well with the experimental observations of Oganessian et al. [Phys. Rev. C 79, 024603 (2009)]. Our study on the isotopes of $Z=120$ predicts that the $\alpha$ decay restricts within the range $277\le A\le 308$ as those isotopes with $A\le 276$ and those nuclei with $A \ge$ 309 do not survive fission. We have also forecasted the mode of decay of ${}^{288-302}120$ superheavy nuclei as six consistent $\alpha$ chains from the nuclei of ${}^{288,289,291-295}120$, seven consistent $\alpha$ chains from the nuclei of ${}^{290}120$, five consistent $\alpha$ chains from the nuclei of ${}^{296,297}120$, and three consistent $\alpha$ chains from the nuclei of ${}^{300-302}120$, which could be of great interest to the experimentalists. The one-proton and two-proton separation energy calculations on ${}^{272-319}120$ superheavy nuclei have revealed that the isotopes spanning the range $273\le A\le 291$ may be considered to be the probable proton emitters.

Figure 1

Plot for the comparison of the calculated $\alpha$-decay half-lives with the corresponding spontaneous fission half-lives of the isotopes ${}^{272-275}120$ and their decay products.

Figure 2

Plot for the comparison of the calculated $\alpha$-decay half-lives with the corresponding spontaneous fission half-lives of the isotopes ${}^{276-279}120$ and their decay products.

Figure 3

Plot for the comparison of the calculated $\alpha$-decay half-lives with the corresponding spontaneous fission half-lives of the isotopes ${}^{280-283}120$ and their decay products.

Figure 4

Plot for the comparison of the calculated $\alpha$-decay half-lives with the corresponding spontaneous fission half-lives of the isotopes ${}^{284-287}120$ and their decay products.

Figure 5

Plot for the comparison of the calculated $\alpha$-decay half-lives with the corresponding spontaneous fission half-lives of the isotopes ${}^{288-291}120$ and their decay products.

Figure 6

Plot for the comparison of the calculated $\alpha$-decay half-lives with the corresponding spontaneous fission half-lives of the isotopes ${}^{292-295}120$ and their decay products.

Figure 7

Plot for the comparison of the calculated $\alpha$-decay half-lives with the corresponding spontaneous fission half-lives of the isotopes ${}^{296-299}120$ and their decay products.

Figure 8

Plot for the comparison of the calculated $\alpha$-decay half-lives with the corresponding spontaneous fission half-lives of the isotopes ${}^{300-303}120$ and their decay products.

Figure 9

Plot for the comparison of the calculated $\alpha$-decay half-lives with the corresponding spontaneous fission half-lives of the isotopes ${}^{304-307}120$ and their decay products.

Figure 10

Plot for the comparison of the calculated $\alpha$-decay half-lives with the corresponding spontaneous fission half-lives of the isotopes ${}^{308-311}120$ and their decay products.

Figure 11

Plot for the comparison of the calculated $\alpha$-decay half-lives with the corresponding spontaneous fission half-lives of the isotopes ${}^{312-315}120$ and their decay products.

Figure 12

Plot for the comparison of the calculated $\alpha$-decay half-lives with the corresponding spontaneous fission half-lives of the isotopes ${}^{316-319}120$ and their decay products.