NuSym23, XIth International Symposium on Nuclear Symmetry Energy

TThe ratio $Y({\pi }^{-})/Y({\pi }^{+})$ (${\pi }^{-}/{\pi }^{+}$) of the yields of the different charge states of $\pi$ is considered an important observable for determining the symmetry energy density in the high-density region. However, there remains much controversy in using it to constrain the resulting symmetry energy. This requires us to further explore the physical mechanisms associated with the production of $\pi$, i.e., the in-medium $\mathrm{\Delta }$ and $\pi$ production and propagation, which are the foundation for reliable determination of the symmetry energy in the future.
In this report, we will show the in-medium $\mathrm{\Delta }$ related inelastic scattering in isospin asymmetric nuclear matter in frame work of the one-boson exchange model. $\mathrm{\Delta }$ and isovector mesons, i.e., $\rho$, $\delta$ are included in order to reasonable describing the isospin asymmetric nuclear matter. Based on this model, we will perform the systemically study on in-medium $NN\to N\mathrm{\Delta }$ , $N\mathrm{\Delta }\to NN$ , $N\pi \to \mathrm{\Delta }$ cross section and $\mathrm{\Delta }\to N\pi$ decay width.