engAvigo, R.Wieland, O.Benzoni, G.Birkenbach, B.Blasi, N.Boston, H. C.Bottoni, S.Brambilla, S.Bruyneel, B.Ciemała, M.Clément, E.Cortes, Martha LilianaBracco, A.Crespi, F. C. L.Cullen, D. M.Curien, D.Didierjean, F.Domingo-Pardo, C.Duchêne, G.Eberth, J.Görgen, A.Gadea, A.Gerl, J.Camera, F.Goel, N.Golubev, P.González, V.Górska, M.Gottardo, A.Gregor, E.Guastalla, GiuliaHabermann, T.Harkness-Brennan, L. J.Jungclaus, A.Ameil, F.Kmiecik, M.Kojouharov, I.Korten, W.Kurz, N.Labiche, M.Lalović, N.Leoni, S.Lettmann, M.Maj, A.Menegazzo, R.Arici, T.Mengoni, D.Merchan, EdanaMillion, B.Morales, A. I.Napoli, D. R.Nociforo, C.Nyberg, J.Pietralla, N.Pietri, S.Podolyák, Zs.Ataç, A.Ponomarev, V. Yu.Pullia, A.Quintana, B.Rainovski, G.Ralet, D.Recchia, F.Reese, M.Regan, P.Reiter, P.Riboldi, S.Barrientos, D.Rudolph, D.Salsac, M. D.Sanchis, E.Sarmiento, L. G.Schaffner, H.Simpson, J.Stezowski, O.Valiente-Dobón, J. J.Wollersheim, H. J.Bazzacco, D.Bednarczyk, P.Low-lying electric dipole ${\gamma}$-continuum for the unstable $^{62,64}Fe$ nuclei: Strength evolution with neutron numberinfo:eu-repo/classification/ddc/53064 Fe62 FeNuclear structureDipole excitation around neutron threshold64Fe62FeThe γ -ray emission from the nuclei $^{62,64}$Fe following Coulomb excitation at bombarding energy of 400-440 AMeV was measured with special focus on E 1 transitions in the energy region 4-8 MeV. The unstable neutron-rich nuclei $^{62,64}$Fe 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 E 1 strength is extracted and compared to microscopic quasi-particle phonon model calculations. The trend of the E 1 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 E 1 nuclear response below the neutron binding energy.Physics letters / B 811, 135951 (2020). doi:10.1016/j.physletb.2020.135951info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionNorth-Holland Publ.2020info:eu-repo/semantics/openAccessDEhttps://repository.gsi.de/record/237998https://repository.gsi.de/search?p=id:%22GSI-2021-00581%22Researchersinfo:eu-repo/semantics/altIdentifier/wos/WOS:000612225400080info:eu-repo/semantics/altIdentifier/doi/10.15120/GSI-2021-00581info:eu-repo/semantics/altIdentifier/issn/1873-2445info:eu-repo/semantics/altIdentifier/doi/10.1016/j.physletb.2020.135951info:eu-repo/semantics/altIdentifier/issn/0370-2693info:eu-repo/grantAgreement/EC//262010