Uncertainties and understanding of experimental and theoretical results regarding reactions forming heavy and superheavy nuclei

TL;DR

This paper reviews experimental and theoretical insights into the probabilities of fusion and survival in reactions forming heavy and superheavy nuclei, highlighting uncertainties and the sensitivity of results to various nuclear parameters.

Contribution

It critically assesses the validity of models and data analysis methods used in studying heavy-ion fusion reactions leading to superheavy elements.

Findings

Strong sensitivity of fusion probability to entrance channel characteristics.

Limitations in current data analysis and theoretical models.

Identification of uncertainties affecting the interpretation of experimental results.

Abstract

Experimental and theoretical results of the $P_{\mathrm{CN}}$ fusion probability of reactants in the entrance channel and the $W_{\mathrm{sur}}$ survival probability against fission at deexcitation of the compound nucleus formed in heavy-ion collisions are discussed. The theoretical results for a set of nuclear reactions leading to formation of compound nuclei (CNs) with the charge number $Z=102\text{--}122$ reveal a strong sensitivity of $P_{\mathrm{CN}}$ to the characteristics of colliding nuclei in the entrance channel, dynamics of the reaction mechanism, and excitation energy of the system. We discuss the validity of assumptions and procedures for analysis of experimental data, and also the limits of validity of theoretical results obtained by the use of phenomenological models. The comparison of results obtained in many investigated reactions reveals serious limits of validity of the data analysis and calculation procedures.