The propagation of σ-meson in nuclear matter is studied in the Walecka model, by assuming that the sigma couples to a pair of nucleon-antinucleon states and to particle-hole states. The in-medium effect of σ-ω mixing is also studied. For completeness, the coupling of sigma to two virtual pions was also considered. It is found that the σ-meson mass decreases with respect to its value in vacuum and that the contribution of the σ-ω mixing effect on the mass shift is relatively small. © Indian Academy of Sciences.
Morones-Ibarra, J. R., Maciel, M. M., Santos-Guevara, A., & Padilla, F. R. (2013). Mass shift of σ-meson in nuclear matter. Pramana - Journal of Physics, 80(3), 479–485. https://doi.org/10.1007/s12043-012-0503-2