Production of Nuclides Near the $N =$ 126 Shell Using Projectiles with $Z$ \textgreater\ 20

Recent experiments at Texas A{\&}M University have shown that the cross sections for fusion-evaporation products in the reactions of $^{48}$Ca, $^{45}$Sc, $^{50}$Ti, and $^{54}$Cr with lanthanide targets are heavily influenced by the atomic number of the projectile. In particular, the cross sections for the 4n evaporation channel in the $^{48}$Ca-induced reactions are substantially larger than for the other projectiles. The compound nuclei in these reactions are near the $N =$ 126 shell, and the sharp decrease in cross section is attributed to an enhancement of the fission level density, along with a smaller change in the probability of compound nucleus formation. Through careful correction for the neutron binding energy, fission barrier, and excitation energy available for neutron emission, it may be possible to use these results to make inferences on the likelihood of future superheavy element synthesis. This talk will discuss recent results and the difficulty of synthesizing evaporation residues using projectiles with $Z$ \textgreater\ 20.