Effect of short-range correlation on the density dependence of nuclear symmetry energy at supra-saturation densities

Short-range correlation (SRC) induces a significant high-momentum component in the nucleon momentum distribution n(k) in both finite nuclei and nuclear matter. Recent experiments suggest that the amount of correlation in pure neutron matter (PNM) may be much less than that in symmetric nuclear matter (SNM). In this paper we investigate on a qualitative level how this affects the density dependence of the symmetry energy, especially at supra-saturation densities, in the framework of the well-established MDI energy density functional. In the MDI formalism, SRC affects both the kinetic energy and the potential energy through its effect on n(k). For the n(k) of SNM, we use a formula proposed based on an interesting relation between n(k) at high momentum k (i.e. k > kF) and the average nucleon density of finite nuclei. For the n(k) of PNM, we use the prediction of a free Fermi gas model. The result is compared to the symmetry energy calculated assuming both the SNM and PNM to be Fermi-gas like. Our study shows that, to have a realistic estimation of the relative contributions to the symmetry energy from the kinetic part and the two-body and three-body potential part, one has to take the SRC effect into account. Furthermore, it is found that the density dependence of the symmetry energy at supra-saturation densities is sensitive to the competition between the SRC effect and the three-body force effect.