A remark on transition probability

Enrico G. Beltrametti, Slawomir Bugajski

Armen D. Sargsyan, A. Tonoyan, G. Hakhumyan +3 more

A one-dimensional nano-metric-thin cell (NC) filled with potassium metal has been built and used to study optical atomic transitions in external magnetic fields. These studies benefit from the remarkable features of the NC allowing one to use and λ methods for effective investigations of individual transitions of the K D 1 line. The methods are based on strong narrowing of the absorption spectrum of the atomic column of thickness L equal to and to λ (with being the resonant laser radiation wavelength). In particular, for a π -polarized radiation excitation the λ -method allows us to resolve eight atomic transitions (in two groups of four atomic transitions) and to reveal two remarkable transitions that we call guiding transitions (GT). The probabilities of all other transitions inside the group (as well as the frequency slope vs . magnetic field) tend to the probability and to the slope of GT. Note that for circular polarization there is one group of four transitions and GT do not exist. Among eight transitions there are also two transitions (forbidden for ) with the probabilities undergoing strong modification under the influence of magnetic fields. Practically the complete hyperfine Paschen-Back regime is observed at relatively low magnetic fields. Note that for the K D 2 line GT are absent. Theoretical models describe the experiment very well.

Fabio Bagarello

Stanley Gudder

C. S. Chang, P. Stehle

We develop a detailed theory to calculate multiple-quantum transition probabilities. It is shown that the quantum electrodynamical (QED) approach must be used in order to explain quantitatively the experimental observations of Kusch. The anomalous behavior of shifts in resonance frequency and saturation of widths of transition probabilities can be explained on the basis of a QED renormalization principle. In this paper, we work out the detailed calculations for the case of a double-quantum transition quantitatively. The agreement between QED calculation and Kusch's observation is remarkable. We conclude that the renormalization principle of QED is important even for low-frequency and finite-intensity fields.

C. Dedes

It is shown that the probability density satisfies a hyperbolic equation of motion with the unique characteristic that in its many-particle form it contains derivatives acting at spatially remote regions. Based on this feature we explore inter-particle correlations and the relation between the quantum equilibrium condition and the permutation invariance of the probability density. Some remarks with respect to the quantum to classical transition are also presented.