The fusion and evaporation residue cross sections for the ${}^{50}$Ti${+}^{249}$Cf and ${}^{54}$Cr${+}^{248}$Cm reactions calculated by the combined dinuclear system and advanced statistical models are compared. These reactions are considered to be used to synthesize the heaviest superheavy element. The ${}^{50}$Ti${+}^{249}$Cf reaction is more mass asymmetric than ${}^{54}$Cr${+}^{248}$Cm, and the fusion excitation function for the former reaction is higher than the one for the latter reaction. The evaporation residue excitation functions for the mass asymmetric reaction is higher in comparison with the one for the ${}^{54}$Cr${+}^{248}$Cm reaction. The use of the mass values of superheavy nuclei calculated in the framework of the macroscopic-microscopic model by the Warsaw Group [Muntian, Z. Patyk, and A. Sobiczewski, Phys. At. Nuclei 66, 1015 (2003)] leads to a smaller evaporation residue cross section for both the reactions in comparison with the case of using the masses calculated by Möller and Nix [J. Phys. G: Nucl. Part. Phys. 20, 1681 (1994)]. The ${}^{50}$Ti${+}^{249}$Cf reaction is more favorable in comparison with the ${}^{54}$Cr${+}^{248}$Cm reaction: the maximum values of the excitation function of the 3$n$ channel of the evaporation residue formation for the ${}^{50}$Ti${+}^{249}$Cf and ${}^{54}$Cr${+}^{248}$Cm reactions are about 0.1 and 0.07 pb, respectively, but the yield of the 4$n$ channel for the former reaction is lower (0.004 pb) in comparison with the one (0.01 pb) for the latter reaction.

• Received 8 September 2011

DOI:https://doi.org/10.1103/PhysRevC.84.044612