Influence of proton shell closure on production of new superheavy nuclei

The shell structure of nuclei with Z > 104 is studied with modified two-center shell model. Using macroscopic-microscopic approach, the mass excesses and Qα-values are calculated and compared with available experimental data. Our calculations reveal quite strong shell effects at Z = 120-126 as well as at N = 184. If our predictions for the heaviest nuclei are correct then one can expect the production of evaporation residues with Z ~ 120 in the reactions 50Ti+249Cf and 54Cr+248Cm with the cross sections 23 and 10 fb, respectively. Nuclei with Z = 120 and N = 178 – 182 are expected to have Qα about 11 MeV and life-time of 0.17 ms – 0.16 s