PT Journal
AU Jungclaus, A
   Doornenbal, P
   Acosta, J
   Vaquero, V
   Browne, F
   Cortes, ML
   Gargano, A
   Koiwai, T
   Naidja, H
   Taniuchi, R
   Tostevin, JA
   Wimmer, K
   Algora, A
   Baba, H
   Fernandez, A
   Lalovic, N
   Nacher, E
   Rubio, B
   Sakurai, H
TI Position of the single-particle 3/2- state in 135Sn and the N = 90 subshell closure
SO Physics Letters B
JI Phys. Lett. B
PY 2024
BP 138561
EP 5pp
VL 851
DI 10.1016/j.physletb.2024.138561
LA English
AB The decay of excited states of the nucleus Sn-135, with three neutrons outside the doubly-magic Sn-132 core, was studied in an experiment performed at the Radioactive Isotope Beam Factory at RIKEN. Several gamma rays emitted from excited Sn-135 ions were observed following one-neutron and one-neutron-one-proton removal from Sn-136 and Sb-137 beams, respectively, on a beryllium target at relativistic energies. Based on the analogy to 133Sn populated via one-neutron removal from Sn-134, an excitation energy of 695(15) keV is assigned to the 3/2(-) state with strongest single-particle character in 135Sn. This result provides the first direct information about the evolution of the neutron shell structure beyond N = 82 and thus allows for a crucial test of shellmodel calculations in this region. The experimental findings are in full agreement with calculations performed employing microscopic effective two-body interactions derived from CD-Bonn and N3LO nucleon-nucleon potentials, which do not predict a pronounced subshell gap at neutron number N=90. The occurrence of such a gap in Sn-140, i.e., when the 1f(7/2) orbital is completely filled, had been proposed in the past, in analogy to the magicity of Ca-48, featuring a completely filled 0f(7/2) orbital one harmonic oscillator shell below.
ER