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The α-decay half-lives of the superheavy nuclei are systematically studied using different versions of proximity potential and a exact method to calculate Coulomb potential between spherical and deformed nuclei in the framework of the double folding model. To reproduce the α-decay half-life, the experimental α-decay energy and Wentzel-Kramers-Brillouin approximation have been used. It is found that the computed values by the Ngô 80 are in good compromise with the experimental half-lives in comparison with other versions. Also, by using this version and within QW S4 for determination α-decay energies for superheavy elements, we had predicted the α-decay half-lives for superheavy nuclei which have not been reported yet. The long half-lives with magnitude about 100 seconds are predicted for the superheavy nuclei which are not in stability islands which indicating remarkable stability in comparison with their neighbors. These results are also in good agreement with the predictions of other semi-empirical formulas.PACS numbers:

The dynamical nucleus-nucleus potentials for some fusion reactions are investigated by using the improved quantum molecular dynamics (ImQMD) model with different sets of parameters in which the corresponding incompressibility coefficient of nuclear matter is different. Two new sets of parameters SKP* and IQ3 for the ImQMD model are proposed with the incompressibility coefficient of 195 and 225 MeV, respectively. The measured fusion excitation function for 16 O+ 208 Pb and the charge distribution of fragments for Ca+Ca and Au+Au in multi-fragmentation process can be reasonably well reproduced. Simultaneously, the influence of the nuclear matter incompressibility and the range of nucleon-nucleon interaction on the nucleus-nucleus dynamic potential is investigated. * Electronic address: wangning@gxnu.edu.cn

Using different types of proximity potentials, we have examined the trend of variations of barrier characteristics (barrier height and its position) as well as fusion cross sections for 50 isotopic systems including various collisions of C, O, Mg, Si, S, Ca, Ar, Ti and Ni nuclei with 1 ≤ N/Z < 1.6 condition for compound systems. The results of our studies reveal that the relationships between increase of barrier positions and decrease of barrier heights are both linear with increase of N/Z ratio. Moreover, fusion cross sections also enhance linearly with increase of this ratio.

Finding the best model to describe the α-decay process is an old and ongoing challenge in nuclear physics. The present work systematically studied α-decay half-lives for the favored ground-state-toground-state transitions of 344 isotopes of nuclei with 52 ≤ Z ≤ 107 using 28 versions of the proximity potential model in the framework of the WKB approximation. The present study introduces the best proximity versions with the fewest deviations with respect to experimental values. The models for Prox. 77-set 4, Prox. 77-set 5, and Dutt 2011 with the root-mean-square deviations (RMSDs) of <1 were found to predict α-decay half-lives better than the other models. Comparison with fusion studies shows that Dutt 2011 is an appropriate model both for α-decay studies and for prediction of the barrier characteristic in heavy-ion fusion reactions. The calculation of α-decay half-lives were repeated for even-even, even-odd, odd-even, and odd-odd nuclei. This detailed comparative study reveals that for these versions the half-lives of the even-even nuclei with RMSDs of <0.6 show less deviation than the even-odd, odd-even, and odd-odd nuclei.* aysan.daei