Real and damped modes for an interacting fermion–antifermion pair: exciton in monolayer mediumAbdullah Guvendi, Semra Gurtas Dogan and Uzeyir YazıcıEur. Phys. J. Plus, 139 4 (2024) 337DOI: https://doi.org/10.1140/epjp/s13360-024-05101-6