First observation of high-K isomeric states in 249Md and 251Md

• Published in: The European physical journal. A, Hadrons and nuclei Vol. 57; no. 12
• Main Authors: Goigoux, T., Theisen, Ch, Sulignano, B., Airiau, M., Auranen, K., Badran, H., Briselet, R., Calverley, T., Cox, D., Déchery, F., Bisso, F. Defranchi, Drouart, A., Favier, Z., Gall, B., Grahn, T., Greenlees, P. T., Hauschild, K., Herzáň, A., Herzberg, R.-D., Jakobsson, U., Julin, R., Juutinen, S., Konki, J., Leino, M., Lightfoot, A., Lopez-Martens, A., Mistry, A., Nieminen, P., Pakarinen, J., Papadakis, P., Partanen, J., Peura, P., Rahkila, P., Rey-Herme, E., Rubert, J., Ruotsalainen, P., Sandzelius, M., Sarén, J., Scholey, C., Sorri, J., Stolze, S., Uusitalo, J., Vandebrouck, M., Ward, A., Zielińska, M., Jachimowicz, P., Kowal, M., Skalski, J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2021; Springer Nature B.V
• Subjects: Configurations; Decay; Elementary excitations; Excitation; Fermi surfaces; Hadrons; Half-life; Heavy Ions; Macroscopic models; Nuclear Fusion; Nuclear Physics; Nuclei; Particle and Nuclear Physics; Physics; Physics and Astronomy; Regular Article - Experimental Physics
• ISSN: 1434-6001; 1434-601X
• DOI: 10.1140/epja/s10050-021-00631-4

Decay spectroscopy of the odd-proton nuclei
249
Md and
251
Md has been performed. High-
K
isomeric states were identified for the first time in these two nuclei through the measurement of their electromagnetic decay. An isomeric state with a half-life of 2.8(5) ms and an excitation energy
≥
910
keV was found in
249
Md. In
251
Md, an isomeric state with a half-life of 1.4(3) s and an excitation energy
≥
844
keV was found. Similarly to the neighbouring
255
Lr, these two isomeric states are interpreted as 3 quasi-particle high-
K
states and compared to new theoretical calculations. Excited nuclear configurations were calculated within two scenarios: via blocking nuclear states located in proximity to the Fermi surface or/and using the quasiparticle Bardeen–Cooper–Schrieffer method. Relevant states were selected on the basis of the microscopic-macroscopic model with a deformed Woods–Saxon potential. The most probable candidates for the configurations of
K
-isomeric states in Md nuclei are proposed.