Study of $N=50$ gap evolution around $Z=32$: new structure information for ${}^{82}$Ge

D Thisse (1) , M Lebois (1, 2) , D Verney (1) , J.N Wilson (1) , N Jovančević , M Rudigier , R Canavan , D Etasse (3) , P Adsley (1) , A Algora , M Babo (1) , K Belvedere , J Benito , G Benzoni , A Blazhev , A Boso , S Bottoni , M Bunce , R Chakma (1) , N Cieplicka-Oryńczak , S Courtin (4) , M.L Cortés , P Davies , C Delafosse (1) , Muriel Fallot (5) , B Fornal , L Fraile , D Gjestvang , A Gottardo , V Guadilla , R. -B Gerst , G Häfner (1) , K Hauschild (1) , M Heine (4) , C Henrich , I Homm , J Hommet (3) , F Ibrahim (1) , Ł. W Iskra , P Ivanov , S Jazrawi , A Korgul , P Koseoglou , T Kröll , T Kurtukian-Nieto (6) , L.Le Meur (5) , S Leoni , J Ljungvall (1) , A Lopez-Martens (1) , R Lozeva (1) , I Matea (1) , K Miernik , J Nemer (1) , S Oberstedt , W Paulsen , M Piersa-Silkowska , W Poklepa , Y Popovitch (1) , C Porzio , L Qi (1) , D Ralet (7) , P.H Regan , D Reygadas-Tello , K Rezynkina , V Sánchez-Tembleque , S Siem , C Schmitt (4) , P. -A Söderström , K Solak , C Sürder , G Tocabens (1) , V Vedia , N Warr , B Wasilewska , J Wiederhold , M Yavahchova , F Zeiser , S Ziliani

1 IJCLab - Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2 IUF - Institut universitaire de France
3 LPCC - Laboratoire de physique corpusculaire de Caen
4 IPHC - Institut Pluridisciplinaire Hubert Curien
5 SUBATECH - Laboratoire de physique subatomique et des technologies associées
6 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan
7 GANIL - Grand Accélérateur National d'Ions Lourds

Medium spin states of light N = 50 isotones have been populated using fast neutron-induced fission of ${}^{232}$Th. Online prompt $\gamma $ spectroscopy has been performed using the hybrid $\gamma $ spectrometer $\nu \text {-}$Ball coupled to the LICORNE directional neutron source at the ALTO facility of IJCLab. Medium spin states of the neutron-rich nucleus ${}^{82}$Ge have been investigated using $\gamma $-$\gamma $ and $\gamma $-$\gamma $-$\gamma $ coincidence data to exploit the resolving power of $\nu \text {-}$Ball. Two new transitions were assigned to this nucleus and a new level was placed in the level scheme. We tentatively assigned to this new state a ($7^{+}$) spin-parity, which is interpreted as a new $N=50$ core breaking state. This provides further insight into the energy evolution of the $N=50$ shell gap toward ${}^{78}$Ni.

Domains: Nuclear Theory [nucl-th]

D Thisse, M Lebois, D Verney, J.N Wilson, N Jovančević, et al.. Study of $N=50$ gap evolution around $Z=32$: new structure information for ${}^{82}$Ge. Eur.Phys.J.A, 2023, 59 (7), pp.153. ⟨10.1140/epja/s10050-023-01051-2⟩. ⟨hal-04170660⟩