- Såmark-Roth, A
- Cox, DM
- Rudolph, D
- Sarmiento, LG
- Carlsson, BG
- Egido, JL
- Golubev, P
- Heery, J
- Yakushev, A
- Åberg, S
- Albers, HM
- Albertsson, M
- Block, M
- Brand, H
- Calverley, T
- Cantemir, R
- Clark, RM
- Düllmann, Ch E
- Eberth, J
- Fahlander, C
- Forsberg, U
- Gates, JM
- Giacoppo, F
- Götz, M
- Götz, S
- Herzberg, R-D
- Hrabar, Y
- Jäger, E
- Judson, D
- Khuyagbaatar, J
- Kindler, B
- Kojouharov, I
- Kratz, JV
- Krier, J
- Kurz, N
- Lens, L
- Ljungberg, J
- Lommel, B
- Louko, J
- Meyer, C-C
- Mistry, A
- Mokry, C
- Papadakis, P
- Parr, E
- Pore, JL
- Ragnarsson, I
- Runke, J
- Schädel, M
- Schaffner, H
- Schausten, B
- Shaughnessy, DA
- Thörle-Pospiech, P
- Trautmann, N
- Uusitalo, J
- et al.
A nuclear spectroscopy experiment was conducted to study α-decay chains stemming from isotopes of flerovium (element Z=114). An upgraded TASISpec decay station was placed behind the gas-filled separator TASCA at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. The fusion-evaporation reactions ^{48}Ca+^{242}Pu and ^{48}Ca+^{244}Pu provided a total of 32 flerovium-candidate decay chains, of which two and eleven were firmly assigned to ^{286}Fl and ^{288}Fl, respectively. A prompt coincidence between a 9.60(1)-MeV α particle event and a 0.36(1)-MeV conversion electron marked the first observation of an excited state in an even-even isotope of the heaviest man-made elements, namely ^{282}Cn. Spectroscopy of ^{288}Fl decay chains fixed Q_{α}=10.06(1) MeV. In one case, a Q_{α}=9.46(1)-MeV decay from ^{284}Cn into ^{280}Ds was observed, with ^{280}Ds fissioning after only 518 μs. The impact of these findings, aggregated with existing data on decay chains of ^{286,288}Fl, on the size of an anticipated shell gap at proton number Z=114 is discussed in light of predictions from two beyond-mean-field calculations, which take into account triaxial deformation.