https://doi.org/10.1140/epja/s10050-019-00001-1
Regular Article - Theoretical Physics
Finite-size effects in heavy halo nuclei from effective field theory
1
Department of Physics, Chalmers University of Technology, 412 96, Gothenburg, Sweden
2
Institute of Nuclear and Particle Physics and Department of Physics and Astronomy, Ohio University, Athens, OH, 45701, USA
3
Institut für Kernphysik, Technische Universität Darmstadt, 64289, Darmstadt, Germany
4
ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany
5
Institut de Physique Nucléaire, CNRS/IN2P3, Université Paris-Sud, Université Paris-Saclay, 91406, Orsay Cedex, France
6
Department of Physics, University of Arizona, Tucson, AZ, 85721, USA
* e-mail: christian.forssen@chalmers.se
Received:
3
May
2019
Accepted:
30
October
2019
Published online:
14
January
2020
Halo/Cluster Effective Field Theory describes halo/cluster nuclei in an expansion in the small ratio of the size of the core(s) to the size of the system. Even in the point-particle limit, neutron-halo nuclei have a finite charge radius, because their center of mass does not coincide with their center of charge. This point-particle contribution decreases as 
, where 
is the mass number of the core, and diminishes in importance compared to other effects, e.g., the size of the core to which the neutrons are bound. Here we propose that for heavy cores the EFT expansion should account for the small factors of . As a specific example, we discuss the implications of this organizational scheme for the inclusion of finite-size effects in expressions for the charge radii of halo nuclei. We show in particular that a short-range operator could be the dominant effect in the charge radius of one-neutron halos bound by a P-wave interaction. The point-particle contribution remains the leading piece of the charge radius for one-proton halos, and so Halo EFT has more predictive power in that case.
© The Author(s), 2020
