  Role of the Coulomb interaction, mean fissility, mass asymmetry, and charge
asymmetry parameters on the synthesis of heavy and superheavy elements has been
examined with respect to the deformation parameters of the projectile and
target nuclei explicitly in light of the experimental results. The observed
facts are classified into four categories and are then used to study several
unsuccessful as well as planned reactions to synthesize the new superheavy
elements $Z= 119, 120$. Concrete inference is too difficult to draw from these
results because of excessive deviations in evaporation residue cross-section
data. It is found that the arbitrary choice of excitation energy for the
experiments studied was the root cause of such large deviations. Such a complex
issue can be resolved well by theoretical excitation function studies using the
advanced statistical model or the dinuclear system model and choosing the
excitation energy corresponding to the energy where the excitation function
curve shows the maximum. We believe this method may help us to predict whether
the estimated evaporation residue cross-section can be measurable within the
experimental limit of the existing facilities for the future reactions planned.
