First experimental isotopic mapping of the fission “γ-bump” and its connection to the Pygmy dipole resonance
Year: 2026
Type: article
Abstract: Nuclear fission produces two excited fragments which fast fly apart. Their properties at scission depend on the dynamics of fission, and rule their return to equilibrium. The present work addresses the excess of γ -rays with energies between 3 and 8 MeV emitted during the fragment de-excitation, revealed in the 80’s but hitherto not fully understood. Combining a state-of-the-art heavy-ion spectrometer and an array of novel scintillators, the island of existence of the so-called “ γ -bump” is delineated, and its topography mapped as a function of fragment emitter proton and neutron numbers for the first time. Its connection to the Pygmy Dipole Resonance is discussed by means of dedicated fission calculations employing microscopic nuclear level densities and γ strength functions. Besides giving insight into the post-scission dynamics of the fragments, the present finding would make fission a new probe of soft dipole modes, complementary to the conventional approaches.
Source: Physics Letters B
Authors: N. Kumar, C. Schmitt, M. Ciemala, A. Maj, A. Lemasson, D. Ramos, M. Rejmund, S. Brambilla, Y. Cho, E. Clément, O. Dorvaux, J. Dudouet, G. de. France, A. Goasduff, B. Jacquot, S. Kihel, M. Lewitowicz, O. Litaize, I. Matea, S. Péru, D.S. Ahn, A.N. Andreyev, P. Bednarczyk, C. Boiano, C. Borcea, A. Bracco, M. Caamano, S. Calinescu, D. Curien, F. Didierjean, G. Duchn̂e, S. Erturk, M. Filliger, M. Forge, B. Fornal, B. Gall, I. Harca, D.G. Jenkins, D.T. Kattikat Melcom, Y.H. Kim, M. Kmiecik, S. Leoni, K. Mazurek, V. Nanal, A. Navin, A. Oberstedt, S. Oberstedt, C. Petrone, J. Piot, B. Sowicki, M. Stanoiu, L. Stuttgé, A. Utepov, M. Ziȩbliński
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7160592429