While mean-field approximations, such as the nuclear shell model, provide a good description of many bulk nuclear properties, they fail to capture the important effects of nucleon–nucleon correlations such as the short-distance and high-momentum components of the nuclear many-body wave function1. Here, we study these components using the effective pair-based generalized contact formalism2,3 and ab initio quantum Monte Carlo calculations of nuclei from deuteron to 40Ca (refs. 4–6). We observe a universal factorization of the many-body nuclear wave function at short distance into a strongly interacting pair and a weakly interacting residual system. The residual system distribution is consistent with that of an uncorrelated system, showing that short-distance correlation effects are predominantly embedded in two-body correlations. Spin- and isospin-dependent ‘nuclear contact terms’ are extracted in both coordinate and momentum space for different realistic nuclear potentials. The contact coefficient ratio between two different nuclei shows very little dependence on the nuclear interaction model. These findings thus allow extending the application of mean-field approximations to short-range correlated pair formation by showing that the relative abundance of short-range pairs in the nucleus is a long-range (that is, mean field) quantity that is insensitive to the short-distance nature of the nuclear force.
Bibliographical noteFunding Information:
We thank J. E. Lynn for providing some of the deuteron momentum distributions. We also thank J. Carlson, C. Ciofi degli Atti, W. Cosyn, S. Gandolfi, A. Lovato, G. A. Miller, J. Ryckebusch, M. Sargsian and M. Strikman for discussions. This work was supported by the US Department of Energy, Office of Science, Office of Nuclear Physics under award nos. DE-FG02-94ER40818, DE-FG02-96ER-40960, DE-AC02-06CH11357, DE-AC05-06OR23177 and DE-SC0013617 (FRIB Theory Alliance Award), the Pazy foundation, and the Israeli Science Foundation (Israel) under grant nos. 136/12 and 1334/16, the NUCLEI SciDAC program, the INCITE program and the Clore Foundation. Computational resources have been provided by the Los Alamos National Laboratory Institutional Computing Program, which is supported by the US Department of Energy National Nuclear Security Administration under contract no. 89233218CNA000001, by the Argonne Leadership Computing Facility at Argonne National Laboratory, which is supported by the US Department of Energy, Office of Science, under contract no. DE-AC02-06CH11357, and by the National Energy Research Scientific Computing Center (NERSC), which is supported by the US Department of Energy, Office of Science, under contract no. DE-AC02-05CH11231.
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