https://doi.org/10.1140/epja/s10050-021-00384-0
Regular Article – Experimental Physics
The neutron dripline at Z = 4: the case of 
1
Département de Physique Nucléaire, IRFU, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette, France
2
LPC Caen, Normandie Université, ENSICAEN, Université de Caen, CNRS/IN2P3, 14050, Caen, France
3
NSCL, East Lansing, USA
Received:
29
December
2020
Accepted:
29
January
2021
Published online:
5
March
2021
We review an extensive study of the beryllium isotopic chain carried out at RIKEN. In particular, we discuss the results on , two key isotopes for the understanding of dineutron configurations and decays in 
. In the 
Be case, a detailed analysis of its spectroscopy, including for the first time a well-founded reaction framework and a realistic three-body model of 
that incorporates core excitations, confirms the dominant 
content of the low-lying spectrum. In the 
Be case, the fragmentation of 
C, a priori free of any selection rules that may have precluded the observation of states in previous experiments, has confirmed the only known state at about 1.8 MeV, assigned according to shell-model calculations to a spin-parity 
. Some perspectives of these studies are also given.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021
