Machine Learning and the Deuteron by Kebble and Rios and Variational Monte Carlo calculations of A≤4 nuclei with an artificial neural-network correlator ansatz by Adams et al.
Adams et al: HLO=−∑i→∇2i2mN+∑i<j(C1+C2→σi⋅→σj)e−r2ijΛ2/4+D0∑i<j<k∑cyce−(r2ik+r2ij)Λ2/4,
where mN is the mass of the nucleon, →σi is the Pauli matrix acting on nucleon i, and ∑cyc stands for the cyclic permutation of i, j, and k. The low-energy constants C1 and C2 are fit to the deuteron binding energy and to the neutron-neutron scattering length