Shapes in the Deuteron

The movie shows a deuteron polarized along the vertical axis

Each frame shows the shape of the deuteron at a specific density, that is the surface that encloses the parts of the deuteron that are at higher density. If there are two surfaces with one inside the other, the inner surface shows the volume excluded by the repulsive core in the NN force.

The densities are shown in each frame in units of nucleons per cubic femtometer (1 fm = 10-15 meter). The density in the center of large nuclei (such as lead nuclei) is approximately 0.16 fm-3, however the highest deutron densities are more than twice this value!

The Argonne v18 potential was used in these calculations. The shapes result from the strong dependence on both spin and space that is present in this and other realistic nucleon-nucleon potentials. For example a proton and neutron 1 fm apart on the vertical axis and in a total spin S = 1 state have a potential that is attractive by 150 MeV if their spins are parallel and repulsive by 150 MeV if the spins are antiparallel.

For more information about shapes in the deuteron and correlations in larger nuclei, see Femtometer toroidal structures in nuclei, by J. L. Forest, V. R. Pandharipande, S. C. Pieper, R. B. Wiringa, R. Schiavilla, and A. Arriaga, Phys. Rev. C 54, 646-667 (1996).
The Argonne v18 potential is described in Accurate nucleon-nucleon potential with charge-independence breaking, by R. B. Wiringa, V. G. J. Stoks, and R. Schiavilla, Phys. Rev. C 51, 38-51 (1995).