Dirac Equations with Confining Potentials
This paper is devoted to a study of relativistic eigenstates of Dirac particles which are simultaneously bound by a static Coulomb potential and added linear confining potentials. Under certain conditions, despite the addition of radially symmetric, linear confining potentials, specific bound-state energies surprisingly preserve their exact Dirac-Coulomb values. The generality of the ≫ preservation mechanism≫ is investigated. To this end, a Foldy-Wouthuysen transformation is used to calculate the corrections to the spin-orbit coupling induced by the linear confining potentials. We find that the matrix elements of the effective operators obtained from the scalar, and time-like confining potentials mutually cancel for specific ratios of the prefactors of the effective operators, which must be tailored to the preservation mechanism. The result of the Foldy-Wouthuysen transformation is used to verify that the preservation is restricted (for a given Hamiltonian) to only one reference state, rather than traceable to a more general relationship among the obtained effective low-energy operators. The results derived from the nonrelativistic effective operators are compared to the fully relativistic radial Dirac equations. Furthermore, we show that the preservation mechanism does not affect antiparticle (negative-energy) states.
J. H. Noble and U. D. Jentschura, "Dirac Equations with Confining Potentials," International Journal of Modern Physics A, vol. 30, no. 1, World Scientific Publishing Co. Pte Ltd, Jan 2015.
The definitive version is available at http://dx.doi.org/10.1142/S0217751X15500025
Keywords and Phrases
Dirac Equation; Foldy-Wouthuysen Method; Linear Confining Potentials
International Standard Serial Number (ISSN)
Article - Journal
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