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Positronium in a liquid phase: formation, bubble state and chemical reactions
This chapter reviews the following items: 1. Energy deposition and track
structure of fast positrons: ionization slowing down, number of ion-electron
pairs, typical sizes, thermalization, electrostatic interaction between e+ and
its blob, effect of local heating; 2. Positronium formation in condensed media:
the Ore model, quasifree Ps state, intratrack mechanism of Ps formation; 3.
Fast intratrack diffusion-controlled reactions: Ps oxidation and ortho-para
conversion by radiolytic products, reaction rate constants, interpretation of
the PAL spectra in water at different temperatures; 4. Ps bubble models.
"Non-point" positronium: wave function, energy contributions, relationship
between the pick-off annihilation rate and the bubble radius
Beyond the Point Ps Approximation
In application to positron annihilation spectroscopy, Ps atom is considered
not as a point particle, but as a finite size e+ e- pair localized in a
bubble-state in a medium. Variation of the internal Coulombic e+ -e- attraction
vs. the bubble radius is estimated
Semiclassical treatment of logarithmic perturbation theory
The explicit semiclassical treatment of logarithmic perturbation theory for
the nonrelativistic bound states problem is developed. Based upon
-expansions and suitable quantization conditions a new procedure for
deriving perturbation expansions for the one-dimensional anharmonic oscillator
is offered. Avoiding disadvantages of the standard approach, new handy
recursion formulae with the same simple form both for ground and exited states
have been obtained. As an example, the perturbation expansions for the energy
eigenvalues of the harmonic oscillator perturbed by are
considered.Comment: 6 pages, LATEX 2.09 using IOP style
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