arXiv subjects

Viktor Hund

Publications and source records attributed to Viktor Hund.

3 recordsLinked to original sources

arXiv1999

$\cal CPT$-invariant two-fermion Dirac equation with extended hyperfine operator

For the S-states of muonium and positronium, the hyperfine shifts to the order $α^6$ of a recently derived two-fermion equation with explicit $\cal CPT$-invariance are checked against the results of a nonrelativistic reduction, and the leading $α^8$ shifts are calculated. An additional hyperfine operator is discovered which can milden the singularity for $r\to 0$ of the Dirac hyperfine operator, such that the resulting extended operator can be used nonperturbatively. The binding correction to magnetic moments is mentioned.

hep-ph↗

arXiv1998

Non-perturbative energy levels of two-fermion bound states

For the S-states of positronium and muonium, the terms of an expansion of energy levels in powers of the fine structure constant $α$ are also members of a "recoil series". The first two terms of that series are calculated to all orders in $α$.

hep-ph↗

arXiv1998

Eight-component two-fermion equations

An eight-component formalism is proposed for the relativistic two-fermion problem. In QED, it extends the applicability of the Dirac equation with hyperfine interaction to the positronium case. The use of exact relativistic two-body kinematics entails a CP-invariant spectrum which is symmetric in the total cms energy. It allows the extension of recent α^6 recoil corrections to the positronium case, and implies new recoil corrections to the fine and hyperfine structures and to the Bethe logarithm.

hep-ph↗