Angular Momentum Limits in Fusion Reactions Induced by Argon and Krypton Projectiles

Evaporation-residue cross sections, $A$ and $Z$ distributions, and $\gamma$-ray multiplicities are reported for ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$ and ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$ reactions leading to various Er compound nuclei. When combined with previous data the results show an angular momentum limit approximately consistent with the expected onset of fission modified by contributions from charged-particle emission. No evidence is found for an absence of evaporation residues from low-$l$ collisions in the ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$ cases.