The nucleus ${}^{54}\mathrm{Zn}$ has been observed for the first time in an experiment at the SISSI/LISE3 facility of GANIL in the quasifragmentation of a ${}^{58}\mathrm{Ni}$ beam at $74.5\mathrm{MeV}/\mathrm{\text{nucleon}}$ in a ${}^{\mathrm{nat}}\mathrm{Ni}$ target. The fragments were analyzed by means of the ALPHA-LISE3 separator and implanted in a silicon-strip detector where correlations in space and time between implantation and subsequent decay events allowed us to generate almost background free decay spectra for about 25 different nuclei at the same time. Eight ${}^{54}\mathrm{Zn}$ implantation events were observed. From the correlated decay events, the half-life of ${}^{54}\mathrm{Zn}$ is determined to be ${3.2}_{-0.8}^{+1.8}\mathrm{ms}$. Seven of the eight implantations are followed by two-proton emission with a decay energy of 1.48(2) MeV. The decay energy and the partial half-life are compared to model predictions and allow for a test of these two-proton decay models.

The $p({}^{11}\mathrm{Li},{}^9\mathrm{Li})t$ reaction has been studied for the first time at an incident energy of $3A\mathrm{MeV}$ at the new ISAC-2 facility at TRIUMF. An active target detector MAYA, built at GANIL, was used for the measurement. The differential cross sections have been determined for transitions to the ${}^9\mathrm{Li}$ ground and first excited states in a wide range of scattering angles. Multistep transfer calculations using different ${}^{11}\mathrm{Li}$ model wave functions show that wave functions with strong correlations between the halo neutrons are the most successful in reproducing the observation.

In an experiment at the SISSI/LISE3 facility of GANIL, we have studied the decay of the two proton-rich nuclei ${}^{45}\mathrm{Fe}$ and ${}^{48}\mathrm{Ni}$. We identified 30 implantations of ${}^{45}\mathrm{Fe}$ and observed for the second time four implantation events of ${}^{48}\mathrm{Ni}$. In 17 cases, ${}^{45}\mathrm{Fe}$ decays by two-proton emission with a decay energy of 1.154(16) MeV and a half-life of $T_{1/2}={1.6}_{-0.3}^{+0.5}$ ms. The observation of ${}^{48}\mathrm{Ni}$ and of its decay allows us to deduce a half-life of $T_{1/2}={2.1}_{-0.7}^{+2.1}$ ms. One out of four decay events is completely compatible with two-proton radioactivity and may therefore indicate that ${}^{48}\mathrm{Ni}$ has a two-proton radioactivity branch. We discuss all information now available on two-proton radioactivity for ${}^{45}\mathrm{Fe}$ and ${}^{48}\mathrm{Ni}$ and compare it to theoretical models.

Quasifree one-proton knockout reactions have been employed in inverse kinematics for a systematic study of the structure of stable and exotic oxygen isotopes at the ${\mathrm{R}}^3\mathrm{B}/\mathrm{LAND}$ setup with incident beam energies in the range of $300–450\mathrm{MeV}/\mathrm{u}$. The oxygen isotopic chain offers a large variation of separation energies that allows for a quantitative understanding of single-particle strength with changing isospin asymmetry. Quasifree knockout reactions provide a complementary approach to intermediate-energy one-nucleon removal reactions. Inclusive cross sections for quasifree knockout reactions of the type ${}^A\mathrm{O}(p,2p){}^{A-1}\mathrm{N}$ have been determined and compared to calculations based on the eikonal reaction theory. The reduction factors for the single-particle strength with respect to the independent-particle model were obtained and compared to state-of-the-art ab initio predictions. The results do not show any significant dependence on proton-neutron asymmetry.

The energy-dependent cross section of the ${}^7\mathrm{Be}(n,\alpha ){}^4\mathrm{He}$ reaction, of interest for the so-called cosmological lithium problem in big bang nucleosynthesis, has been measured for the first time from 10 meV to 10 keV neutron energy. The challenges posed by the short half-life of ${}^7\mathrm{Be}$ and by the low reaction cross section have been overcome at n_TOF thanks to an unprecedented combination of the extremely high luminosity and good resolution of the neutron beam in the new experimental area (EAR2) of the n_TOF facility at CERN, the availability of a sufficient amount of chemically pure ${}^7\mathrm{Be}$, and a specifically designed experimental setup. Coincidences between the two alpha particles have been recorded in two $\mathrm{Si}\text{−}{}^7\mathrm{Be}\text{−}\mathrm{Si}$ arrays placed directly in the neutron beam. The present results are consistent, at thermal neutron energy, with the only previous measurement performed in the 1960s at a nuclear reactor. The energy dependence reported here clearly indicates the inadequacy of the cross section estimates currently used in BBN calculations. Although new measurements at higher neutron energy may still be needed, the n_TOF results hint at a minor role of this reaction in BBN, leaving the long-standing cosmological lithium problem unsolved.