

Artikel
Dirac resonance energies for central potentials with different Lorentztype potential couplings
Författare: 
Thylwe, K.E. 
Dokumenttyp: 
Artikel 
Tillstånd: 
Publicerad 
Tidskrift: 
Physica Scripta 
Volym: 
81
035007 
År: 
2010 
AbstractThe amplitudephase method is applied to relativistic Diracparticle resonances related to electronatom collisions. Complexenergy resonance poles of the $S$ matrix in central potentials of differing Lorentz couplings are studied near the nonrelativistic limit. It is confirmed that an equal mixture of a Lorentz vectortype (with a single time component) and a Lorentz scalartype potential of the same radial shape makes the interaction essentially spinindependent, 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 Schr\"{o}dinger limit and in the KleinGordon equation. In a Lorentzvector 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 usually is a characteristic feature of semiclassical methods.

