Gauge-invariant Dirac-Fock approach to electron internal conversion in nuclides: Dynamic enhancement and chaos elements

Standard approach to calculating the electron conversion characteristics is based on the usual non-relativistic Hartree-Fock or Hartree-Fock-Slater approach with account of the finite nuclear size. More correct calculation uses the relativistic approaches, in particular, the well known Dirac-Fock method Though this approach is one of the most wide-spread calculation methods, but, as a rule, the corresponding Dirac-Fock orbital basis’s are not optimized. It often lead to the quite large errors in calculating the fundamental atomic characteristics. Besides, some problems are connected with correct definition of the nuclear size effects, radiative corrections etc. We present here ab initio gauge-invariant Dirac-Fock approach to definition of spectra, wave functions basis’s for the heavy isotopes with account of relativistic, correlation, nuclear, QED effects. The basis is provided by the gauge-invariant QED perturbation theory [1]. We consider spectra of the barium isotopes and turn attention on definition of the corresponding internal conversion electron coefficients. It is confirmed that the E1 transitions between parity doublets are characterized by a two to four orders of magnitude enhancement compared to those of more normal cases [2]. A possibility of manifestation of stochastic elements (dynamic enhancement) and quantum chaos is discussed.

References:
1. Glushkov A.V., Relativistic Quantum Theory, Odessa: Astroprint, 2008.-900P.
2. Serga I.N., Photoelectronics, 18, 71-76 (2009).