24 research outputs found
Triaxial superdeformation in Ar
Superdeformed (SD) states in Ar have been studied using the
deformed-basis antisymmetrized molecular dynamics. Low energy states were
calculated by the parity and angular momentum projection (AMP) and the
generator coordinate method (GCM). Basis wave functions were obtained by the
energy variation with a constraint on the quadrupole deformation parameter
, while other quantities such as triaxiality were optimized by
the energy variation. By the GCM calculation, an SD band was obtained just
above the ground state (GS) band. The SD band involves a side
band due to the triaxiality. The calculated electric quadrupole transition
strengths of the SD band reproduce the experimental values appropriately.
Triaxiality is significant for understanding low-lying states.Comment: 11 pages, 4 figure
Rotational level structure of sodium isotopes inside the "island of inversion"
The neutron-rich nuclei 33,34,35Na were studied via in-beam γ-ray spectroscopy following nucleon removal reactions from a 36Mg secondary beam at ~220 MeV/u. Excited states of 34,35Na are reported for the first time. A third transition was observed for 33Na in addition to the known 7/2+ 1 → 5/2+ 1 → 3/2+ g.s. cascade and is suggested to be the 9/2+ 1 → 7/2+ 1 transition. Similarly, a 7/2+ 1 → 5/2+ 1 → 3/2+ g.s. cascade is proposed for the decay pattern observed for 35Na. The transition energy ratios are close to expectation values for K = 3/2 rotational bands in the strong coupling limit. Comparisons to large-scale shell model calculations in the sd-p f model space support the spin-parity assignments. © The Author(s) 2014.published_or_final_versio
Identification of 45 New Neutron-Rich Isotopes Produced by In-Flight Fission of a 238U Beam at 345 MeV/nucleon
A search for new isotopes using in-flight fission of a 345 MeV/nucleon 238U
beam has been carried out at the RI Beam Factory at the RIKEN Nishina Center.
Fission fragments were analyzed and identified by using the superconducting
in-flight separator BigRIPS. We observed 45 new neutron-rich isotopes: 71Mn,
73,74Fe, 76Co, 79Ni, 81,82Cu, 84,85Zn, 87Ga, 90Ge, 95Se, 98Br, 101Kr, 103Rb,
106,107Sr, 108,109Y, 111,112Zr, 114,115Nb, 115,116,117Mo, 119,120Tc,
121,122,123,124Ru, 123,124,125,126Rh, 127,128Pd, 133Cd, 138Sn, 140Sb, 143Te,
145I, 148Xe, and 152Ba