Static and dynamic characteristics of various mesons and the deuteron. Dissertation Thesis

The Dissertation is concerned of static and dynamic characteristics of various mesons and the deuteron, which are defined in the Introduction. Special attention is payed to the electromagnetic polarizabilities of pions in the Chapter I and the Chapter II. While in the Chapter I is represented a review of present theoretical and experimental situation of the pion polarizabilities, in the Chapter II the problem of an ambiguous determination of the sum and the difference of the neutral pion polarizabilities is solved by the unambiguous determination of a meson parameters with the help of the pion scalar form factor and the calculation and the two photon decay of σ meson in the framework of the linearized Nambu-Jona-Lasinio type Lagrangian. In the Chapter III the new deuteron - proton sum rule is derived, by means of which and data on the corresponding physical quantities in the sum rule the mean -square - charge radius of the deuteron is numerically evaluated to be in a satisfactory agreement with the dispersion relations prediction. In the Chapter IV by means of the special Lagrangian of the quark - meson interactions the decay width of φ → f₀(980)γ and the total cross - section of the e⁺e^- → γ^* → φf₀(980) process is predicted. In the last Chapter V we have tried to solve the conflict between the measured and theoretically predicted branching ratio of the process π⁰ → e⁺e^- decay by the inclusion of the double - logarithmic QED radiative corrections. Despite of the latter, the discrepancy between the theoretical prediction and the experimental result for the π⁰ → e⁺e^- decay was not removed and further independent experimental and theoretical efforts have to be continued. (Author)