abstract

A detailed study of energy dependence of \(\frac {K^-}{K^+}\) ratio has been carried out in nucleus–nucleus (\(AA\)) collisions (Pb+Pb collisions at \(\sqrt {s_{NN}}=6.3\) GeV and 17.3 GeV, Au+Au collisions at \(\sqrt {s_{NN}}=19.6\)–200 GeV) and in \(pp\) collisions at \(\sqrt {s}=6.3\)–200 GeV in the framework of UrQMD and DPMJET III models. It has been observed that as energy increases, the \(\frac {K^-}{K^+}\) ratio increases systematically for both nucleus–nucleus and \(pp\) collisions. A comparison of our analysis with the analysis of the experimental data has also been presented wherever available. Our analysis is well-supported by the experimental results obtained by different collaborations in different times.

abstract

We provide here a theoretical frame for Quantum Hadro-Dynamics able to provide a well-behaved approximation scheme that preserves sum rules and general theorems. This scheme is extended to strange particles. A mean field evaluation follows, including strangeness in the ground state, so to reproduce the hypernuclei properties. The theoretical frame is constructed in such a way that the calculation at the Next-To-Leading-Order becomes only a numerical problem.

abstract

The derivation of the phase transition in the model of Gaździcki and Gorenstein is generalized and simplified by using a geometrical construction.

abstract

In this article, we provide the canonically deformed classical Henon–Heiles system. Further we demonstrate that for proper value of deformation parameter \(\theta \), there appears chaos in the model.

abstract

Here are presented results of the coarse-grained Metropolis Monte Carlo simulation of the random walk performed by the biomolecular growth unit at the crystal surface during the protein crystallization process. The surface-to-solution energy exchange that occurs during the movement of the “walker” can be considered in terms of colour noise. The presence of the noise can impede the interpretation of the results obtained e.g. by the dynamic scattering methods. To characterize the noise, the power spectra are generated and analysed. The characteristic non-universal noise exponent is temperature- and surface morphology-dependent.

abstract

The divergent series for a function defined through Lapalce integral and the ground state energy of the quartic anharmonic oscillator to large orders are studied to test the generalized binomial transform which is the renamed version of \(\delta \) expansion proposed recently. We show that, by the use of the generalized binomial transform, the values of functions in the limit of zero of an argument are approximately computable from the series expansion around the infinity of the same argument. In the Laplace integral, we investigate the subject in detail with the aid of Mellin transform. In the anharmonic oscillator, we compute the strong coupling limit of the ground state energy and the expansion coefficients at strong coupling from the weak coupling perturbation series. The obtained result is compared with that of the linear delta expansion.