Lamb shift

The Lamb shift is an effect in quantum physics, which was discovered in 1947 by Willis Eugene Lamb and Robert Retherford Curtis ( 1912-1981 ).

The Dirac theory suggests that states with the same principal quantum number and the same total angular momentum quantum number of the hydrogen or hydrogen-like atoms or ions are degenerate. The Lamb shift now causes a lifting of degeneracy between the two energy levels and due to quantum electrodynamic effects.

Meanwhile, the term also applies to other energy shifts levels.

The lifting of degeneracy is caused by vacuum fluctuations, where ever, in accordance with the Heisenberg uncertainty principle, particle-antiparticle pairs created ( pairing ) and annihilate ( annihilation). The existence of the particle-antiparticle pairs causes a small deviation from the Coulomb interaction. Therefore, a small correction to the calculation of the potential energy to be added, which can be approximately written as follows:

With

• Atomic number Z
• Elementary charge e
• Electric field constant
• Distance r.

Also contributing to the Lamb shift supply vertex corrections and self-energy insertions of the electron and the proton, which interact with each other. The vacuum polarization contributes ordinary atoms with electron shell only slightly in the Lamb - shift; she falls in muonic atoms more weight. The Lamb shift arises as to:

Respectively

In which

• The fine structure constant
• The mass of the electron
• The quantum number and
• A small number (< 0.05) is.