Low-lying electric dipole γ-continuum for the unstable ^62,64Fe nuclei: Strength evolution with neutron number

Summary, in English

The γ-ray emission from the nuclei ^62,64Fe following Coulomb excitation at bombarding energy of 400-440 AMeV was measured with special focus on E1 transitions in the energy region 4-8 MeV. The unstable neutron-rich nuclei ^62,64Fe were produced at the FAIR-GSI laboratories and selected with the FRS spectrometer. The γ decay was detected with AGATA. From the measured γ-ray spectra the summed E1 strength is extracted and compared to microscopic quasi-particle phonon model calculations. The trend of the E1 strength with increasing neutron number is found to be fairly well reproduced with calculations that assume a rather complex structure of the 1⁻ states (three-phonon states) inducing a strong fragmentation of the E1 nuclear response below the neutron binding energy. © 2020 The Author(s)

• Author: R. Avigo; O. Wieland; A. Bracco; F. Camera; F. Ameil; Pavel Golubev; Nataša Lalović; Dirk Rudolph; Luis Sarmiento Pico; H.J. Wollersheim
• Department/s: Nuclear physics
• Publishing year: 2020
• Language: English
• Publication/Series: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
• Volume: 811
• Links: http://dx.doi.org/10.1016/j.physletb.2020.135951
• Document type: Journal article
• Publisher: Elsevier
• Topic: Subatomic Physics
• Keywords: 62Fe; 64Fe; Dipole excitation around neutron threshold; Nuclear structure
• Status: Published
• Project: FAIR-NUSTAR: HISPEC-DESPEC experiment & Super-FRS contributions; Nuclear Structure at the Limits: Isotope-selective Spectroscopy
• ISBN/ISSN/Other: ISSN: 0370-2693