Background: Observation of asymmetric fission of ${}^{180}\mathrm{Hg}$ has led to intensive theoretical and experimental studies of fission of neutron-deficient nuclei in the lead region.

Background: The nature of asymmetric fission of preactinides is not yet understood in detail, despite intense experimental and theoretical studies carried out at present.

The pathway toward the production of superheavy elements (SHE) crosses with the one of an in-depth study of the fission and quasifission processes. Quasifission affects the probability of forming a compound nucleus (CN) after capture and fission plays a decisive role during the cooling of the CN. To search for optimal reactions to produce SHE in fusion reactions and to provide an estimate of their production cross section measurements of the capture and fusion cross sections along with the survival probabilities are a mandatory task. Here an overview of the impact of fission and quasifission over the synthesis of SHE is discussed along with the need to perform measurements over a wide range of masses and energies.

The ridge structure with Δ${\mathit{E}}_{\gamma }$=±30 keV, recently observed in the reaction 187 MeV ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$ ${+}^{120}$Sn and attributed to a hyperdeformed nuclear shape, has been confirmed in a new proton-γ coincidence experiment and assigned to the ${}_{}{}^{152}{}_{}{}^{}\mathrm{Dy}$ nucleus. Estimates of the cross section for the population of the 30 keV ridge and for the associated entry states have been obtained. The proton spectra in coincidence with γ rays of different Dy isotopes show effects related to the exit channel and to the angular momentum but they are scarcely sensitive to the selection of different shapes (oblate, normal deformed prolate, superdeformed) in the same residual nucleus ${}_{}{}^{152}{}_{}{}^{}\mathrm{Dy}$. The energy of the protons in coincidence with the Δ${\mathit{E}}_{\gamma }$=±30 keV ridge is however larger than expected. This effect is discussed in the framework of the fission-evaporation competition.

The elastic scattering in the reaction $$^{7}$$7 Li+ $$^{208}$$208 Pb was investigated in the bombarding energy range from 25 to 39 MeV. The real and imaginary parts of the optical potential were analyzed by using a phenomenological potential. A dispersion relation analysis is presented in order to investigate the threshold anomaly effect. It is concluded that $$^{7}$$7 Li has an intermediate behavior between the tightly bound nuclei such as $$^{16}$$16 O and the loosely bound nuclei such as $$^{6}$$6 Li where the lack of the threshold anomaly is unambiguously observed. Reaction cross sections are also extracted from the elastic scattering data and its comparison with the ones of other systems has been performed to draw hints on the effect of the breakup channel.

The transfer-induced fission channel has been studied in the collision of 340 MeV ${}^{28}\mathrm{Si}$ on ${}^{232}\mathrm{Th}$ as a function of the atomic number of the projectilelike fragments (PLF’s) by using a $4\pi$ detector array. It is found that the energy loss of the transfer reaction increases as a function of the net charge transfer $\Delta Z$ from the projectile to the target nucleus, going from quasielastic to deep-inelastic regimes. The average excitation energy of the targetlike fragment (TLF) is derived from the measured energy loss, whereas its angular momentum has been obtained from the angular distribution of fission fragments. It is found that the populated TLF nuclei with $Z_{\mathrm{TLF}}=90\mathrm{}–96\hspace{0.5em}(\Delta Z=0\mathrm{}–6)$ have average excitation energies up to about 100 MeV and angular momenta up to about $40ħ.$ The measured ratio of transfer-fission yield to PLF singles, $Y_f,$ first increases with increasing net charge transfer up to $\Delta Z=4\mathrm{}$ and then shows a plateau around the values $Y_f=0.4\mathrm{}–0.6$ followed by a decrease for higher $\Delta Z$ transfers. This ratio can be identified as the cumulative fission probability of the populated nuclei for net charge transfers up to $\Delta Z<~6,$ where a two-body mechanism for the first reaction step is supported by the experimental data. This result suggests a significant survival probability against fission of these TLF nuclei, in marked disagreement with the standard statistical model predictions. The observed survival probability implies that there is a strong hindrance to fission in the early stages of deexcitation, as also indicated by the large fission times ${(t}_f=10\mathrm{}–100\hspace{0.5em}\mathrm{zs})$ derived from earlier neutron measurements in fusion-fission reactions. The importance of such effects in the population of nuclei in the heavy and superheavy mass regions by transfer reactions is discussed.