Diffusion as a possible mechanism controlling the production of superheavy nuclei in cold fusion reactions

The fusion probability for the production of superheavy nuclei in cold fusion reactions was investigated and compared with recent experimental results for 48Ca, 50Ti, and 54Cr incident on a 208Pb target. Calculations were performed within the fusion-by-diffusion model (FbD) using the new nuclear data tables by Jachimowicz et al. [At. Data Nucl. Data Tables 138, 101393 (2021)]. It is shown that the experimental data could be well explained within the framework of the FbD model. The saturation of the fusion probability at bombarding energies above the interaction barrier is reproduced. It emerges naturally from the physical effect of the suppression of contributions of higher partial waves in fusion reactions. The role of the difference in values of the rotational energies in the fusion saddle point and contact (sticking) configuration of the projectile-target system is discussed.