1. First observation of high-K isomeric states in $$^{249}$$Md and $$^{251}$$Md
- Author
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F. Defranchi Bisso, P. Jachimowicz, Mikael Sandzelius, Paul Greenlees, Kalle Auranen, P. Peura, Ch. Theisen, R.-D. Herzberg, R. Julin, P. Rahkila, T. Grahn, M. Vandebrouck, J. Skalski, A. Drouart, Jan Sarén, R. Briselet, H. Badran, T. Calverley, J. Rubert, Joonas Konki, P. Nieminen, Matti Leino, B. J. P. Gall, Daniel Cox, A. Ward, C. Scholey, M. Kowal, U. Jakobsson, M. Airiau, F. Déchery, Philippos Papadakis, Panu Ruotsalainen, Jari Partanen, Janne Pakarinen, Z. Favier, Juha Uusitalo, T. Goigoux, B. Sulignano, A. Lopez-Martens, M. Zielińska, K. Hauschild, S. Stolze, E. Rey-Herme, A. K. Mistry, Juha Sorri, S. Juutinen, A. Herzáň, A. Lightfoot, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Nuclear and High Energy Physics ,Nuclear Theory ,nucl-th ,[PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th] ,isomeria ,Hadron ,FOS: Physical sciences ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,nucl-ex ,7. Clean energy ,01 natural sciences ,Nuclear Theory (nucl-th) ,0103 physical sciences ,Nuclear fusion ,Nuclear Physics - Experiment ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,010306 general physics ,Spectroscopy ,Physics ,010308 nuclear & particles physics ,Fermi surface ,State (functional analysis) ,puoliintumisaika ,Nuclear Physics - Theory ,Excited state ,Quasiparticle ,Atomic physics ,ydinfysiikka ,Excitation - Abstract
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 $\ge 910$ 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 $\ge 844$ 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. 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 $\geq 910$ 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 $\geq 844$ 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.
- Published
- 2021
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