Dirac resonance energies for central potentials with different Lorentz-type potential couplings
2010 (English)In: Physica Scripta, ISSN 0031-8949, E-ISSN 1402-4896, Vol. 81, no 3Article in journal (Refereed) Published
The amplitude-phase method is applied to relativistic Dirac-particle resonances related to electron-atom collisions. Complex-energy resonance poles of the S matrix in central potentials of differing Lorentz couplings are studied near the non-relativistic limit. It is confirmed that an equal mixture of a Lorentz vector-type potential (with a single time component) and a Lorentz scalar-type potential of the same radial shape makes the interaction essentially spin independent, as if spin does not couple to orbital angular momentum. Hence, resonance poles of the S matrix depend simply on the orbital angular momentum and the radial quantum number in a similar way as in the Schrodinger limit and in the Klein-Gordon equation. In a Lorentz-vector potential model, there is a splitting of pole positions, but the splitting may be surprisingly small, as demonstrated for one of the potentials considered. The numerical method used automatically assigns a vibrational (radial) quantum number to the resonance state, which is usually a characteristic feature of semiclassical methods.
Place, publisher, year, edition, pages
2010. Vol. 81, no 3
schrodinger-equation, numerical-solutions, approximation, fermions, states
IdentifiersURN: urn:nbn:se:kth:diva-19284DOI: 10.1088/0031-8949/81/03/035007ISI: 000275223000007OAI: oai:DiVA.org:kth-19284DiVA: diva2:337331
QC 201005252010-08-052010-08-052011-01-21Bibliographically approved