Angular correlation spectra of $e^{+}{e}^{-}$ pairs produced in the ${}^3\mathrm{H}(p,e^{+}{e}^{-}){}^4\mathrm{He}$ nuclear reaction have been studied at $E_p=510$, 610, and 900 keV proton energies. The main features of the spectra can be understood by taking into account the internal and external pair creations following the proton capture by ${}^3\mathrm{H}$. However, these processes cannot account for an observed peak around ${115}^{\circ }$ in the angular correlation spectra. This anomalous excess of $e^{+}{e}^{-}$ pairs can be described by the creation and subsequent decay of a light particle during the direct capture process. The derived mass of the particle is $m_{\mathrm{X}}{c}^2=16.94\pm 0.12\left(\mathrm{stat}\right)\pm 0.21\left(\mathrm{syst}\right)$ MeV. According to the mass this is likely the same X17 particle, which we recently suggested [ Phys. Rev. Lett. 116, 042501 (2016)] for describing the anomaly observed in the decay of ${}^8\mathrm{Be}$.

High-spin states of ${}^{98,99,100}\mathrm{Ru}$ have been populated using the reaction ${}^{70}\mathrm{Zn}{(}^{36}\mathrm{S},\alpha \mathrm{x}n)$ at 130 MeV. The $\gamma$ rays have been detected with the EUROGAM-2 array. New high-spin bands have been established in these nuclei and interpreted as terminating configurations using the Nilsson-Strutinsky cranking formalism. These bands were observed up to the predicted terminating states which are built from $g_{9/2}$ protons and $N=3\mathrm{}$ proton holes combined with $d_{5/2},$ $g_{7/2},$ and $h_{11/2}$ neutrons relative to a ${}^{90}\mathrm{Zr}$ core. Core-excited configurations with $N=3\mathrm{}$ proton holes have been found to play an important role. The observed high-spin states assigned as terminating show systematic behavior and provide new information on the energy spacing between the ${2d}_{5/2}$ and ${1g}_{7/2}$ neutron subshells.

The nuclei ${}^{230}\mathrm{U}$ and ${}^{232}\mathrm{U}$ were populated in the compound nucleus reactions ${}^{232}\mathrm{Th}$($\alpha ,6n$) and ${}^{232}\mathrm{Th}$($\alpha ,4n$), respectively. Gamma rays from these nuclei were observed in coincidence with a recoil detector. A comprehensive set of in-band $E2$ transitions were observed in the lowest lying negative-parity band of ${}^{232}\mathrm{U}$ while one $E2$ transition was also observed for ${}^{230}\mathrm{U}$. These allowed $B(E1;I^{-}\to I^{+}-1)/B(E2;I^{-}\to I^{-}-2)$ ratios to be extracted and compared with systematics. The values are similar to those of their Th and Ra isotones. The possibility of a tetrahedral shape for the negative-parity U bands appears difficult to reconcile with the measured $Q_2$ values for the isotone ${}^{226}\mathrm{Ra}$.

Recently, we measured the e$^+$e$^-$ angular correlations in internal pair creation (IPC) for the M1 transitions depopulating the 17.6 and 18.15 MeV states in $^8$Be, and observed a peak-like deviation from the predicted IPC for the 18.15 MeV transition, but not for the 17.6 MeV one. To the best of our knowledge no nuclear physics related description of such deviation can be made. The deviation between the experimental and theoretical angular correlations is significant and can be described by assuming the creation and subsequent decay of a boson with mass $m_0c^2$=16.70$\pm0.35 $(stat)$\pm 0.5 $(sys) MeV. The branching ratio of the e$^+$e$^-$ decay of such a boson to the $\gamma$ decay of the 18.15 MeV level of $^8$Be is found to be $5.8\times10^{-6}$ for the best fit. The data can be explained by a 17.6 MeV vector gauge boson X that is produced in the decay of the excited state to the ground state, and then decays to e$^+$e$^-$ pairs. In the present work we re-investigated the e$^+$e$^-$ pair correlation in the 17.6 MeV transition of $^8$Be in which some smaller deviation was also expected. The branching ratio of the $e^+e^-$ decay of such a boson to the $\gamma$ decay was found to be $(2\pm2)\times10^{-6}$.

High spin states have been populated in ${}^{102}\mathrm{Rh}$ using the reaction ${}^{70}\mathrm{Zn}{(}^{36}\mathrm{S},p3n\gamma )$ at 130 MeV. The γ rays have been detected with the EUROGAM2 array. The level structure of ${}^{102}\mathrm{Rh}$ has been investigated. Several bands have been identified and established over a wide range of spin. They are interpreted using the Nilsson-Strutinsky cranking formalism and explained in terms of band terminations. Their configurations are built from the valence particles and valence holes relative to a ${}^{90}\mathrm{Zr}$ core: $g_{9/2}$ protons (and $N=3\mathrm{}$ proton holes) and $d_{5/2},$ $g_{7/2},$ and $h_{11/2}$ neutrons. After ${}^{102}\mathrm{Pd},$ ${}^{102}\mathrm{Rh}$ is the second heavy nucleus and the first odd-odd nucleus in which configurations in the valence space are followed from low spin up to their termination.

Recently, when examining the differential internal pair creation coefficients of ⁸Be, ⁴He and ¹²C nuclei, we observed peak-like anomalies in the angular correlation of the e⁺e⁻ pairs. This was interpreted as the creation and immediate decay of an intermediate bosonic particle with a mass of $m_X{c}^2\approx$ 17 MeV, receiving the name X17 in subsequent publications. In this paper, our latest results obtained for the X17 particle are presented by investigating the e⁺e⁻ pair correlations in the decay of the Giant Dipole Resonance (GDR) of ⁸Be. Our results initiated a significant number of new experiments all over the world to detect the X17 particle and determine its properties. In this paper, we will also conduct a mini-review of the experiments whose results are already published, as well as the ones closest to being published.