abstract

The rate of barrier crossing in a cusped potential serves as a model for electron transfer processes in the presence of dissipation. The spatial diffusion limit for the rate constant is known for this case in the strong damping limit when the Smoluchowski equation is valid. The paper discusses comparison of different approximation schemes in derivation of a one dimensional Smoluchowski equation for a linear kinetic model derived by a non-Markovian dynamics. Differences in calculated short- and longtime limit properties of the systems resulting from various method of elimination of fast variables question validity of use of a Smoluchowski equation in the kinetic rate approach. To calculate the rate, the standard definition in the integrated form of the correlation function is used and the results are shown to be consistent with the predictions of numerical analysis presented in literature.

abstract

We show that if vector current conservation is consistently implemented, an interesting subclass of graphs relevant for the strong interaction corrections to atomic parity violation has a vanishing small effect on the determination of \(\sin ^2 \theta _W\).

abstract

We introduce the parameter of bunching for analysis of intermittent structure of multihadron production at high-energy collisions following analogy with photon counting in quantum optics. It is shown the existence of a power-law singularity for second-order bunching parameter in small phase-space intervals for monofractal structure of multiplicity distribution and the similar form of high-order parameters for multifractality. The approximation of the high-order bunching parameters by the second-order provides goad description of anomalous fractal dimensions for some experimental data with multifractal behaviour.

abstract

Characteristics of reactions \(dp \to ppp\pi ^-\), \(np \to pp\pi ^-\), \(dp \to dp\pi ^+\pi ^-\), \(np \to d\pi ^+\pi ^-\), \(dp \to dn\pi ^+\) at 1.7 GeV/c per nucleon have been studied. By comparison of \(dp\) and \(np\) interactions the different mechanisms in deuteron reactions were separated and it was shown that the quasi free nucleon–proton process is dominant. More unambiguous selection of spectators was demonstrated simultaneously. Their momenta distributions were well described by the known deuteron wave functions up to 0.4 GeV/c. It was shown that exotic effects at high momenta contribute in less than 3% of events.

abstract

Cross Sections for the \((n, p)\) reaction on \(^{96,99,101,102,104}\)Ru isotopes have been adequately explained in terms of the statistical multistep direct and the novel statistical multistep compound reaction model.

abstract

In the unified temperature dependent nuclear model with Woods–Saxon single particle potential the adiabatic mass parameters and potential energies are calculated and discussed. Both liquid drop and shell correction are temperature dependent. Shell structure of mass parameter and fission barriers vanish for hot nuclear systems at \(T = 1.5\) MeV. The mass parameter is shown to have irrotational behaviour at high temperature.

abstract

The friction tensor is evaluated within the linear response theory and the zero frequency limit approximation. The calculation are performed for \(^{156}\)Dy at a deformation corresponding to the top of the fission barrier. The deformed Nilsson potential is used to describe the intrinsic degrees of freedom. It is found that the component of the friction tensor connected with the elongation mode grows significantly when the reflection symmetry of the nucleus is broken.