NUC In the literature: partially resolved

Simultaneous binding energies and charge radii of medium-mass nuclei

In plain words

First-principles calculations with many common nuclear forces either bind medium-mass nuclei correctly but make them too small, or get the size right and the binding wrong. The cause is thought to lie in the three-nucleon force (a force that acts only when three nucleons are close together).

Precise statement

With NN plus 3N interactions from chiral EFT fitted only to few-body data ($A \le 4$, optionally nuclear-matter saturation), predict ground-state energies and charge radii of 16O, 40Ca, 48Ca and 208Pb within 1 percent, and saturation of symmetric nuclear matter ($n_0$ about $0.16\ \mathrm{fm}^{-3}$, $E/A$ about $-16\ \mathrm{MeV}$). Answer: an interaction with quantified truncation errors meeting these targets, and identification of the 3N terms that control saturation.

What would settle it

Ab initio calculations with Bayesian uncertainty quantification reproducing binding and radii from 4He to 208Pb using interactions fixed in few-body systems.

Status in the literature

Unverified note

$\Delta$-full chiral interactions fitted to light-nucleus and nuclear-matter data (Jiang et al., 2020) improved radii and binding together, but predictions remained sensitive to the fit protocol as of 2026.