We present the first fully unrestricted microscopic calculations of the primary fission fragment intrinsic spins and of the fission fragments relative orbital angular momentum for $^{236}$U$^*$, $^{240}$Pu$^*$, and $^{252}$Cf using the time-dependent
density functional theory framework. Within this microscopic approach, free of restrictions and unchecked assumptions and which incorporates the relevant physical observables relevant for describing fission, we evaluate the triple distribution of the fission fragment intrinsic spins and of their fission fragments relative orbital angular momentum and show that their dynamics is dominated by their bending collective modes, in contradistinction to the predictions of the existing phenomenological models and some interpretations of experimental data.
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 sec
tion in nuclear medium to reproduce the experimental $pi^pm$ multiplicities, 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 $pi^+$ production may indicate the need for including the strong potential on $pi^pm$ in RVUU, which is at present absent. Predictions on the centrality dependence of proton rapidity distribution and transverse momentum spectrum are also presented.
