International Journal of Theoretical Physics
Spin-0 and Spin-1 Bosonic Particles Dynamics in $$(1+3)$$ Dimensions via the Relativistic DKP Equation with a Spatially-Dependent Exponential Mass Term
P. Mah Tsila, Sylvère Yannick Loemba Mouandza, A. Atangana Likéné, Serge Mbida Mbembe, E. Anemena Etoga, H. D. Yia Etolo, Germain Hubert Ben-Bolie
Abstract
Abstract The Duffin-Kemmer-Petiau (DKP) equation is a relativistic wave equation governing the dynamics of spin-0 and spin-1 bosonic particles. In this work, we study the $$(1+3)$$ ( 1 + 3 ) -dimensional DKP equation with a spatially dependent mass under a modified deformed exponential type potential. Using the framework of supersymmetric quantum mechanics, we derive approximate analytical solutions. A novel extension of the Pekeris approximation is introduced to treat the centrifugal barrier, enabling the complete determination of the energy spectrum. The non-relativistic limit of the DKP equation is obtained via an established transformation technique. The model is applied to diatomic molecules including lithium hydride (LiH), hydrogen chloride (HCl), $$^{7}\textrm{Li}_{2}$$ 7 Li 2 , $$\textrm{Na}_{2}$$ Na 2 , and ScI. The energy spectra are computed for various quantum states $$\left| n,l,j\right\rangle $$ n , l , j using both relativistic and non-relativistic expressions. For LiH and HCl, where experimental data are scarce, our results show strong agreement with earlier theoretical predictions. For $$^{7}\textrm{Li}_{2}$$ 7 Li 2 , $$\textrm{Na}_{2}$$ Na 2 , and ScI, the calculated energies align excellently with available experimental data. The proposed framework provides a reliable and analytically tractable tool for studying bosonic systems with position-dependent effective masses.