Charged pion production from Au + Au collisions at $\sqrt{s_{NN}}=2.4$ GeV in the Relativistic Vlasov-Uehling-Uhlenbeck model

Using the isospin-dependent relativistic Vlasov-Uehling-Uhlenbeck (RVUU) model, we study charged pion ($\pi^\pm$) production in Au+Au collisions at $\sqrt{s_{NN}}=$ 2.4 GeV. By fitting the density dependence of the $\Delta$ resonance production cross section in nuclear medium to reproduce the experimental $\pi^\pm$ multiplicities measured by the HADES Collaboration, we obtain a good description of the rapidity distributions and transverse momentum spectra of $\pi^\pm$ in collisions at various centralities. Some shortcomings in the description of $\pi^{\pm}$ production may indicate the need for including the strong potential on $\pi^\pm$ in RVUU, which is at present absent. We also calculate the proton rapidity distribution in the most central collisions and compare with the coalescence invariant proton rapidity distribution extracted from preliminary HADES data.Comment: 7 pages, 5 figures, version to appear in PL