Nuclear symmetry energy and the role of the tensor force

Using the Hellmann-Feynman theorem we analyze the contribution of the different terms of the nucleon-nucleon interaction to the nuclear symmetry energy $E_{\mathrm{sym}}$ and the slope parameter $L$. The analysis is performed within the microscopic Brueckner-Hartree-Fock approach using the Argonne V18 potential plus the Urbana IX three-body force. We find that the main contribution to $E_{\mathrm{sym}}$ and $L$ comes from the tensor component of the nuclear force.