High-K, t$_{1/2}$ = 1.4(1) ms, isomeric state in $^{255}$Lr

K. Hauschild (1) , A. Lopez-Martens (1) , A. V. Yeremin , O. Dorvaux (2) , S. Antalic , A. V. Belozerov , Ch. Briançon (1) , M. L. Chelnokov , V. I. Chepigin , D. Curien (2) , B. Gall (2) , A. Görgen (3) , V. A. Gorshkov , M. Guttormsen , F. Hanappe , A. P. Kabachenko , F. Khalfallah (2) , A. C. Larsen , O. N. Malyshev , A. Minkova , A. G. Popeko , Marc Rousseau (2) , N. Rowley (2) , S. Saro , A. V. Shutov , S. Siem , L. Stuttgè (2) , A. I. Svirikhin , N. U. H. Syed , Ch. Theisen (3) , M. Venhart

1 CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse
2 DRS-IPHC - Département Recherches Subatomiques
3 DPHN - Département de Physique Nucléaire (ex SPhN)

isomeric state in 255Lr with a half-life of t1/2 = 1.4(1) ms and Ex>720-keV has been observed for the first time using the GABRIELA setup at the focal plane of the VASSILISSA separator. Based on its K-forbiddeness, the configuration of the state is most probably formed by coupling the valence proton to a two quasiparticle neutron excitation. Possible three quasiparticle configurations are discussed.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

K. Hauschild, A. Lopez-Martens, A. V. Yeremin, O. Dorvaux, S. Antalic, et al.. High-K, t$_{1/2}$ = 1.4(1) ms, isomeric state in $^{255}$Lr. Physical Review C, 2008, 78, pp.021302-4. ⟨10.1103/PhysRevC.78.021302⟩. ⟨in2p3-00318833⟩