A survey of Coulomb displacement energies and questions on the anomalous behavior in the upper ${\sf fp}$-shell

Abstract

The recent advances in nuclear mass measurement have sparked discussions on the isospin-symmetry breaking reflected in the Coulomb displacement energy (CDE). The current data suggested that the regular phase of the odd-even staggering in CDE for the T = 1/2 mirror nuclei persists up to A = 67 and changes at A = 69. Shell-model calculations using the modern GXPF1A and JUN45 effective interactions with a proper treatment of the Coulomb and isospin-nonconserving forces cannot describe the observation. Inspired by recent work (Kaneko 2013 Phys. Rev. Lett. 110 172505), we investigate the systematic behavior of CDE along the N = Z line up to the heaviest available masses. Starting from A ≈ 65, a systematic deviation is observed between the experimental data and the model estimations assuming the nucleus as a homogeneously charged sphere. Possibilities that may resolve the conflict between the experimental mass and theoretical expectations for the 69 Br-region are discussed, and new mass experiments are called for.

Studies at the border between nuclear and atomic physics: Weak decays of highly charged ions

“…The successful research program at CSRe concentrates on direct mass measurements of exotic nuclides, see Refs. [103][104][105][106][107][108][109][110][111][112]. At RIKEN, the R3 storage ring is located behind the BigRips fragment separator.…”

Radioactive decays of highly-charged ions

“…With novel highly-sensitive Schottky detectors [63], nondestructive measurements on single ions became also possible also in the IMS [64]. The IMS technique is successfully applied not only at the ESR but also at the experimental cooler-storage ring CSRe [83,84] at the Institute of Modern Physics in Lanzhou [85,86,87,88,89,90,91,92,93,94] and will become the main operation mode of the RI-RING at RIKEN [95,96].…”

Electroweak Decays of Highly Charged Ions

“…The storage ring mass spectrometry makes use of cocktail beams and is applied successfully at the ESR [56][57][58][59][60][61][62][63][64][65][66][67] and CSRe [68][69][70][71][72][73][74][75][76][77]. The R3 is being commissioned now and is expected to begin with mass measurements already in 2018.…”