High pt squeezed-out n /p ratio as a probe of Ksym of the symmetry energy

By involving the constraints of the slope of nuclear symmetry energy L into the question of determination of the high-density symmetry energy, one needs to probe the curvature of nuclear symmetry energy K_sym. Based on the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model, effects of the curvature of nuclear symmetry energy on the squeezed-out nucleons are demonstrated in the semicentral Au +Au reaction at 400 and 600 MeV/nucleon. It is shown that the squeezed-out isospin-dependent nucleon emissions at high transverse momenta are sensitive to the curvature of nuclear symmetry energy. The curvature of nuclear symmetry energy at saturation density thus can be determined by the high-momentum squeezed-out isospin-dependent nucleon emissions experiments from the semicentral Au +Au reaction at 400 or 600 MeV/nucleon.