Low-Energy Magnetic Dipole Radiation in Open-Shell Nuclei

Decoherence of collective motion in warm nuclei

“…[10] associated the experimentally observed enhancement of the GSF below 2 MeV with the calculated spike at E γ = 0, which they called Low Energy Magnetic Radiation (LEMAR). The presence of exponential LEMAR spike in weakly deformed nuclei was confirmed by subsequent Shell Model studies along the same line for the Fe isotopes [11] and the nuclei in the fp-shell [9, 12, 13] (and earlier work cited).…”

“…The impact on the M1 GSF was studied in Ref. [11] for the 60,64,68 Fe isotopes by means of Shell Model calculations using Z = 20 and N = 28 as a core. The calculations account for the increase of quadrupole collectivity in the considered isotopic chain.…”

“…Taking GSF for 64 Fe into consideration, the authors of Ref. [11] concluded that the bimodal structure gradually develops with increasing N by shifting strength from the LEMAR spike to the SR while the sum stays nearly constant. The gradual development of the SR and the shift of the integrated strength when entering a shell has been confirmed experimentally for odd-A Sm isotopes [18].…”

Cascade calculation with schematic interactions

“…Indeed in ref [5] we were able to get some analytic results for wave functions and transitions from the ground state, especially in the weak coupling limit. in contrast to [6] and [8][9][10][11][12] we present our results as log plots. Brown and Larsen also used a log plot [7].…”

“…It should be made clear that our basic aim is to study the properties of the matrix Hamiltonian of Table 1. We will not attempt to fit the results of [6][7][8][9][10][11][12] but we will see if there are some common features that might be of interest.…”