Influência do momento de dipolo magnético anômalo do elétron em átomos de alto número atômico

Abstract

In this work we study the behaviour of very-heavy atoms (Z > 100). When Zα > ǀKǀ, Dirac's equation in the usual minimal coupling does not yield physically acceptable values for the electron state energies in presence of a point nuclens. For such values of Z, the wave-functions show a rather irregular and physically meaningless behaviour as r →0. This difficult disappears when the finite size of the nucleus is acknowledged. Here we show that taking into account the contribution from Anomalous Magnetic Dipole Moment of the electron, whithin a point nucleus model, is a sufficient condition to obtain regular wave-functions and physically meaningful energy éingen - values for all Z. The two theories present different results in a quantitative pointes of view. However, the interesting concepts that appear within the finite nucleus model, such as the diving of the bound states into the negative energy continuum at certain critical values of Z, the spontaneous production of positrons and charged vacuum concept are also present in this new focalization. The anomalous magnetic moment is introduced in the hamiltonian in a fenomenological way, since the radiative corrections do not corresponds to reality for such high atomic numbers. As a quantitative result, we have found 159 for the critical Z for 1S waves, while in the finite. nuclear model this number is 172. We also suggest, subjected to future confirmation, that if one considers in block, the finite size of the nucleus, the anomalous magnetic dipole moment and the electron-electron interactions, one should find Zcr ≅ 174 for the ground state.