Measurement of the β⁺ and orbital electron-capture decay rates in fully ionized, hydrogenlike, and helium like ¹⁴⁰Pr ions

Yu. A. Litvinov (1, 2) , F. Bosch (2) , H. Geissel (2, 1) , J. Kurcewicz , Z. Patyk , N. Winckler , L. Batist , K. Beckert (2) , D. Boutin (3) , C. Brandau , Lin Chen (4) , C. Dimopoulou (2) , B. Fabian (1) , T. Faestermann (5) , A. Fragner (6) , L. Grigorenko , E. Haettner (1) , S. Hess (7) , P. Kienle (6, 5) , R. Knoebel , C. Kozhuharov (2) , S. A. Litvinov , L. Maier , M. Mazzocco , F. Montes (2) , G. Muenzenberg , A. Musumarra (8) , C. Nociforo (2) , F. Nolden (2) , M. Pfuetzner , W. R. Plass , A. Prochazka (2) , R. Reda , R. Reuschl (2) , C. Scheidenberger (2) , M. Steck (2) , T. Stoehlker , S. Torilov , Martino Trassinelli (9) , B. Sun (10, 11) , H. Weick (2) , M. Winkler (2)

1 JLU - Justus-Liebig-Universität Gießen = Justus Liebig University
2 GSI - Helmholtz zentrum für Schwerionenforschung GmbH
3 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
4 NJUST - Nanjing University of Science and Technology
5 TUM - Technische Universität Munchen - Technical University Munich - Université Technique de Munich
6 SMI - Stefan Meyer Institut für subatomare Physik
7 CETP - Centre d'étude des environnements terrestre et planétaires
8 DAPNIA - Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée
9 INSP - Institut des Nanosciences de Paris
10 Key Laboratory of Cenozoic Geology and Environment
11 Shandong Geological Sciences Institute

We report on the first measurement of the β⁺ and orbital electron-capture decay rates of ¹⁴⁰Pr nuclei with the simplest electron configurations: bare nuclei, hydrogenlike, and heliumlike ions. The measured electron-capture decay constant of hydrogen like ¹⁴⁰Pr⁵⁸⁺ ions is about 50% larger than that of helium like ¹⁴⁰Pr⁵⁷⁺ ions. Moreover, ¹⁴⁰Pr ions with one bound electron decay faster than neutral ¹⁴⁰Pr⁰⁺ atoms with 59 electrons. To explain this peculiar observation one has to take into account the conservation of the total angular momentum, since only particular spin orientations of the nucleus and of the captured electron can contribute to the allowed decay.

Domaines: Matière Condensée [cond-mat]

Yu. A. Litvinov, F. Bosch, H. Geissel, J. Kurcewicz, Z. Patyk, et al.. Measurement of the β⁺ and orbital electron-capture decay rates in fully ionized, hydrogenlike, and helium like ¹⁴⁰Pr ions. Physical Review Letters, 2007, 99 (26), pp.262501. ⟨10.1103/PhysRevLett.99.262501⟩. ⟨hal-01281102⟩