Generalized nuclear contacts and momentum distributions

The general nuclear contact matrices are defined, taking into consideration all partial waves and finite-range interactions, extending Tan's work on the zero range model. The properties of these matrices are discussed and the relations between the contacts and the one-nucleon and two-nucleon momentum distributions are derived. Using these relations, a new asymptotic connection between the one-nucleon and two-nucleon momentum distributions, describing the two-body short-range correlations in nuclei, is obtained. Using available numerical data, we extract a few connections between the different contacts and verify their relations to the momentum distributions. The numerical data also allows us to identify the main nucleon momentum range affected by two-body short-range correlations. Utilizing these relations and the numerical data, we also verify a previous independent prediction-connecting between the Levinger constant and the contacts. This work provides an important indication for the relevance of the contact formalism to nuclear systems, and should open the path for revealing more useful relations between the contacts and interesting quantities of nuclei and nuclear matter.

Figure 1

The ratio $(2F_{pp}+F_{pn})/n_p$ for different nuclei. The numerical data are taken from Ref. [9]. Red line—${}^4\mathrm{He}$, green line—${}^6\mathrm{He}$, cyan line—${}^8\mathrm{He}$, black line—${}^6\mathrm{Li}$, blue line—${}^8\mathrm{Be}$, and pink line—${}^{10}\mathrm{B}$. The dashed red line is the reference $y=1$.

Figure 2

The ratio $(2F_{nn}+F_{pn})/n_n$ for the nonsymmetric nuclei in the numerical data of Ref. [9]. Blue line—${}^6\mathrm{He}$, and green line—${}^8\mathrm{He}$. The dashed red line is the reference $y=1$.

Figure 3

The ratio between $F_{pp}$ and $F_{nn}$ in the same nuclei for the available nonsymmetric nuclei in [9]. Blue line—${}^6\mathrm{He}$, and red line—${}^8\mathrm{He}$. The dashed blue and red lines indicate the value of $Z/N$ in ${}^6\mathrm{He}$, and ${}^8\mathrm{He}$, respectively.

Figure 4

The ratio between $F_{pp}\left(X\right)$ and $F_{pp}{(}^4\mathrm{He})$ for the available nuclei $X$ in the numerical data of Ref. [9]. Blue line—${}^6\mathrm{He}$, red line—${}^8\mathrm{He}$, green line—${}^6\mathrm{Li}$, black line—${}^8\mathrm{Be}$, and pink line—${}^{10}\mathrm{B}$.

Figure 5

The ratio between $F_{pn}\left(X\right)$ and $n_p{(}^2\mathrm{H})$ for the available nuclei $X$ in the numerical data of Ref. [9]. Blue line—${}^4\mathrm{He}$, red line—${}^6\mathrm{He}$, green line—${}^8\mathrm{He}$, black line—${}^6\mathrm{Li}$, pink line—${}^8\mathrm{Be}$, and cyan line—${}^{10}\mathrm{B}$.