Ab initio predictions link the neutron skin of Pb-208 to nuclear forces
Journal article, 2022
Heavy atomic nuclei have an excess of neutrons over protons, which leads to the formation of a neutron skin whose thickness is sensitive to details of the nuclear force. This links atomic nuclei to properties of neutron stars, thereby relating objects that differ in size by orders of magnitude. The nucleus Pb-208 is of particular interest because it exhibits a simple structure and is experimentally accessible. However, computing such a heavy nucleus has been out of reach for ab initio theory. By combining advances in quantum many-body methods, statistical tools and emulator technology, we make quantitative predictions for the properties of Pb-208 starting from nuclear forces that are consistent with symmetries of low-energy quantum chromodynamics. We explore 10(9) different nuclear force parameterizations via history matching, confront them with data in select light nuclei and arrive at an importance-weighted ensemble of interactions. We accurately reproduce bulk properties of Pb-208 and determine the neutron skin thickness, which is smaller and more precise than a recent extraction from parity-violating electron scattering but in agreement with other experimental probes. This work demonstrates how realistic two- and three-nucleon forces act in a heavy nucleus and allows us to make quantitative predictions across the nuclear landscape. Predictions of the properties of Pb-208 from first principles augmented by statistical learning techniques reproduce those seen in experiments but rule out very thick neutron skins.
Author
Baishan Hu
TRIUMF
Weiguang Jiang
Chalmers, Physics, Subatomic, High Energy and Plasma Physics
Takayuki Miyagi
Technische Universität Darmstadt
Helmholtz
TRIUMF
Zhonghao Sun
Oak Ridge National Laboratory
University of Tennessee
Andreas Ekström
Chalmers, Physics, Subatomic, High Energy and Plasma Physics
Christian Forssén
Chalmers, Physics, Subatomic, High Energy and Plasma Physics
Gaute Hagen
Oak Ridge National Laboratory
TRIUMF
University of Tennessee
Jason D. Holt
McGill University
TRIUMF
Thomas Papenbrock
Oak Ridge National Laboratory
University of Tennessee
S. Ragnar Stroberg
Argonne National Laboratory
University of Washington
Ian Vernon
Durham University
Nature Physics
1745-2473 (ISSN) 17452481 (eISSN)
Vol. 18 10 1196-1200Subject Categories
Physical Sciences
DOI
10.1038/s41567-022-01715-8