https://doi.org/10.1140/epja/s10050-021-00410-1
Review
Probing nuclear forces beyond the nuclear drip line: the cases of 
F and 
F
A Tribute to Mahir Hussein
1
Grand Accélérateur National d’Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Bvd Henri Becquerel, 14076, Caen, France
2
IJCLab, Université Paris-Saclay, CNRS/IN2P3, 91405, Orsay, France
3
LPC Caen, ENSICAEN, Normandie Université, CNRS/IN2P3, Caen, France
4
Departamento de Física, Universidade Federal de São Paulo, CEP 09913-030, São Paulo, Diadema, Brazil
5
CEA Saclay, Irfu, DPhN, Université Paris-Saclay, 91191, Gif-sur-Yvette, France
6
Horia Hulubei National Institute of Physics and Nuclear Engineering, P.O. Box MG6, Bucharest-Margurele, Romania
7
Vinča Institute of Nuclear Sciences, University of Belgrade, Belgrade, Serbia
8
Institute of Nuclear Physics, PAS, Radzikowskiego 152, 31342, Kraków, Poland
9
Nuclear Physics Institute of the Czech Academy of Sciences, CZ-250 68, Rez, Czech Republic
10
Instituto de Física, Universidade de São Paulo, CEP 05508-090, São Paulo, SP, Brazil
11
Department of Physics, University of Tokyo, Hongo 7-3-1, Bunkyo, 113-0033, Tokyo, Japan
12
Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou, China
13
School of Nuclear Science and Technology, University of Chinese Academy of Sciences, 100049, Beijing, China
14
Department of Integrated Sciences, Centro de Estudios Avanzados en Física, Matemáticas y Computación (CEAFMC), University of Huelva, 21071, Huelva, Spain
15
RIKEN Nishina Cente, Tokyo, Japan
16
Technische Universität Darmstadt, Darmstadt, Germany
Received:
6
January
2021
Accepted:
1
March
2021
Published online:
12
March
2021
The unbound proton-rich nuclei F and F are investigated experimentally and theoretically. Several experiments using the resonant elastic scattering method were performed at GANIL with radioactive beams to determine the properties of the low lying states of these nuclei. Strong asymmetry between F–N and F–C mirror nuclei is observed. The strength of the 
effective interaction involving the loosely bound proton in the 
orbit is significantly modified with respect to their mirror nuclei N and C. The reduction of the effective interaction is estimated by calculating the interaction energies with a schematic zero-range force. It is found that, after correcting for the effects due to changes in the radial distribution of the single-particle wave functions, the mirror symmetry of the 
interaction is preserved between F and N, while a difference of 63% is measured between the 
versus 
interactions in the second excited state of F and C nuclei. Several explanations are proposed.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021
