Short-range correlations in isospin symmetric and asymmetric nuclear matter: A microscopic perspective

Short-range correlations in nuclear and neutron matter are examined through the properties of the correlated wave function obtained by solving the Bethe–Goldstone equation. Tensor correlations are explored through the dominant tensor-driven transition and central correlations through the singlet and triplet $S$ waves. Predictions from a popular meson-theoretic nucleon-nucleon potential employed in the Dirac–Brueckner–Hartree–Fock approach are compared with those from two- and three-body high-quality chiral interactions in Brueckner $G$-matrix calculations. Short-range correlations in symmetric matter are remarkably stronger than in neutron matter. It is found that short-range correlations are very model dependent and have a large impact on the symmetry energy above normal density.

Figure 1

Magnitude squared of the defect function Eq. (4) for the ${}^3{S}_1\text{−}{{}^{3}D}_1$ transition (left) and the ${}^3{S}_1$ state (right) in symmetric nuclear matter. The Fermi momentum is equal to 1.4 ${\mathrm{fm}}^{-1}$.

Figure 2

Magnitude squared of the defect function Eq. (4) for the ${}^1{S}_0$ state in asymmetric matter with $\alpha =0.4$. The Fermi momentum corresponding to the total nucleonic density is equal to 1.4 ${\mathrm{fm}}^{-1}$. The dotted (blue), dashed (green), and dash-dotted (purple) curves are calculated by using the $pp$, $nn$, and $pnG$ matrices, respectively, with the appropriate Pauli operators and isospin coefficients. See text for more details.

Figure 3

The magnitude squared of Eq. (4) for three different values of the Fermi momentum in symmetric matter: $k_F=1.1$ ${\mathrm{fm}}^{-1}$ (solid red); $k_F=1.4$ ${\mathrm{fm}}^{-1}$ (dashed green); $k_F=1.7$ ${\mathrm{fm}}^{-1}$ (dotted blue).

Figure 4

Leading three-body forces at ${\mathrm{N}}^2\mathrm{LO}$. See text for more details.

Figure 5

Blue (dotted) line shows standard prediction of the magnitude squared of the defect function from the DBHF calculations together with the Bonn B potential. Green (dashed) line shows prediction with the chiral two-body interaction only. Red (solid) line shows prediction with two- and three-body chiral interactions. Symmetric nuclear matter with Fermi momentum is equal to 1.4 ${\mathrm{fm}}^{-1}$.

Figure 6

The symmetry energy as a function of density predicted with various interaction models, as explained in the text.