Dipole Strength Distribution of He 8 and Decay Characteristics
Journal article, 2026
The weak binding and spatially extended neutron densities characteristic of drip-line nuclei give rise to a distinctive low-energy dipole response. The drip-line nucleus He8 is the most neutron-rich bound nucleus with a mass-to-charge ratio of A/Z=4. We measure the dipole response of He8, including for the first time the four-neutron decay channel. A total dipole strength of ∑B(E1)(E∗<15 MeV)=0.95(16)e2 fm2 and a dipole polarizability of αD=0.61(1) fm3 are extracted from the differential Coulomb-excitation cross section and compared to state-of-the-art theoretical calculations employing coupled cluster and three-body approaches. We find that the dipole continuum is dominated, even at high excitation energies well above the 4n decay threshold, by two-neutron emission, pointing to a He6+2n structure of the excited dipole mode. No indication was found for a 4n final-state correlation, while pronounced nn and He6-n final-state correlations are apparent.
Author
C. Lehr
Technische Universität Darmstadt
T. Aumann
Technische Universität Darmstadt
Helmholtz Association of German Research Centres
M. Duer
Technische Universität Darmstadt
A. T. Saito
Institute of Science Tokyo
Takashi Nakamura
Institute of Science Tokyo
N. L. Achouri
Normandie University
D. Ahn
RIKEN
H. Baba
RIKEN
S. Bacca
Johannes Gutenberg University Mainz
C.A. Bertulani
Texas A&M University
M. Böhmer
Technical University of Munich
Francesca Bonaiti
Michigan State University
Oak Ridge National Laboratory
Johannes Gutenberg University Mainz
K. Boretzky
Helmholtz Association of German Research Centres
C. Caesar
RIKEN
Helmholtz Association of German Research Centres
Technische Universität Darmstadt
N. Chiga
RIKEN
D. Cortina-Gil
University of Santiago de Compostela (USC)
C. A. Douma
University of Groningen
F. Dufter
Technical University of Munich
Z. Elekes
Debreceni Egyetem
Hungarian Academy of Sciences
J. Feng
Peking University
B. Fernandez-Dominguez
University of Santiago de Compostela (USC)
U. Forsberg
University of York
N. Fukuda
RIKEN
I. Gasparic
Technische Universität Darmstadt
RIKEN
Ruder Boskovic Institute
Z. Ge
RIKEN
R. Gernhäuser
Technical University of Munich
J. M. Gheller
University Paris-Saclay
J. Gibelin
Normandie University
A. Gillibert
University Paris-Saclay
K. Hahn
Ewha Womans University
Institute for Basic Science
Z. Halász
Hungarian Academy of Sciences
M. N. Harakeh
University of Groningen
A. Hirayama
Institute of Science Tokyo
M. Holl
Technische Universität Darmstadt
N. Inabe
RIKEN
T. Isobe
RIKEN
J. Kahlbow
Technische Universität Darmstadt
N. Kalantar-Nayestanaki
University of Groningen
D. Kim
Institute for Basic Science
S. Kim
Technische Universität Darmstadt
Institute for Basic Science
T. Kobayashi
Tohoku University
Y. Kondo
Institute of Science Tokyo
D. Körper
Helmholtz Association of German Research Centres
P. Koseoglou
Technische Universität Darmstadt
Y. Kubota
RIKEN
P. J. Li
Fudan University
The University of Hong Kong
S. Lindberg
Y. Liu
Peking University
F. M. Marqués
Normandie University
S. Masuoka
University of Tokyo
M. Matsumoto
Institute of Science Tokyo
J. Mayer
University of Cologne
K. Miki
Tohoku University
Technische Universität Darmstadt
M. Miwa
RIKEN
B. Monteagudo
Normandie University
A. Obertelli
University Paris-Saclay
Technische Universität Darmstadt
N. A. Orr
Normandie University
H. Otsu
RIKEN
V. Panin
RIKEN
Helmholtz Association of German Research Centres
S. Y. Park
Institute for Basic Science
Ewha Womans University
M. Parlog
Normandie University
S. Paschalis
Technische Universität Darmstadt
University of York
P. M. Potlog
Institute for Space Sciences, Bucharest
S. Reichert
Technical University of Munich
A. Revel
Large Heavy Ion National Accelerator (GANIL)
Michigan State University
Normandie University
D. Rossi
Technische Universität Darmstadt
R. Roth
Technische Universität Darmstadt
M. Sasano
RIKEN
H. Scheit
Technische Universität Darmstadt
F. Schindler
Technische Universität Darmstadt
T. Shimada
Institute of Science Tokyo
S. Shimoura
University of Tokyo
H. Simon
Helmholtz Association of German Research Centres
S. Storck-Dutine
Technische Universität Darmstadt
L. Stuhl
Institute for Basic Science
University of Tokyo
H. Suzuki
RIKEN
D. Symochko
Technische Universität Darmstadt
H. Takeda
RIKEN
S. Takeuchi
Institute of Science Tokyo
J. Tanaka
RIKEN
Technische Universität Darmstadt
Y. Togano
Institute of Science Tokyo
T. Tomai
Institute of Science Tokyo
Hans Törnqvist
Technische Universität Darmstadt
Helmholtz Association of German Research Centres
J. Tscheuschner
Technische Universität Darmstadt
T. Uesaka
RIKEN
V. Wagner
Technische Universität Darmstadt
H. Yamada
Institute of Science Tokyo
B. Yang
Peking University
L. Yang
University of Tokyo
Z. Yang
RIKEN
M. Yasuda
Institute of Science Tokyo
K. Yoneda
RIKEN
Lorenzo Zanetti
Technische Universität Darmstadt
J. Zenihiro
RIKEN
Kyoto University
Physical Review Letters
0031-9007 (ISSN) 1079-7114 (eISSN)
Vol. 136 17 172501Subject Categories (SSIF 2025)
Theoretical Chemistry
Atom and Molecular Physics and Optics
Subatomic Physics
DOI
10.1103/vp3m-5rpp