Hyperon polarization from meson-baryon reactions in regge models

The hyperon polarization resulting in high-energy meson–baryon strangeness-exchange processes is discussed. The general predictions of various Regge models are compared with experiment. It is shown that the absorption corrections to the strongly degenerate pair of K*(890) K**(1420) trajectories describe correctly the observed polarization. The qualitative predictions for cross-sections are also discussed

Numerical modelling of Bose-Einstein correlations

We propose extension of the algorithm for numerical modelling of Bose-Einstein correlations (BEC), which was presented some time ago in the literature. It is formulated on quantum statistical level for a single event and uses the fact that identical particles subjected to Bose statistics do bunch themselves, in a maximal possible way, in the same cells in phase-space. The bunching effect is in our case obtained in novel way allowing for broad applications and fast numerical calculations. First comparison with $e^+e^-$ annihilations data performed by using simple cascade hadronization model is very encouraging.Comment: LaTeX file and 5 eps file with figures, 9 pages altogethe

Correlation integrals for charged and neutral pions in inclusive production and the two-component picture

The existing data on multiplicity distribution of charged and neutral pions produced in high-energy interactions are analysed in terms of correlation integrals. The two-component picture of particle production is used to explain the data. The model is shown to describe correctly the two- and three-particle correlations between charged pions as well as the two-particle correlations between charged and neutral pions. The possible detailed versions of the model differing at highest energies are discussed

Forward-backward correlations in the multiple production

We discuss the minimal model for the forward-backward correlations in the hadron- and lepton-induced multiple production. In this model correlations are generated by averaging over the components corresponding to the independent emission of clusters with different average multiplicities. We show that the model corrected approximately for phase-space effects describes reasonably well the high energy hadronic data. On the other hand, the test of its applicability to the lh or e$^{+}$e$^{-}$ data requires higher energies than presently available

The Bose-Einstein effect and the joint WW decay

The influence of the Bose - Einstein interference effect on the joint WW hadronic decay is discussed. It is shown that the weight method incorporating this effect into Monte Carlo generators produces in a natural way an excess of average multiplicity as compared to the independent decay of two W bosons. The quantitative results for the average multiplicity and momentum distribution of charged pions, obtained with a simple parametrization of weights compatible with the observed shape of the "Bose - Einstein ratio", agree well with the existing data.Comment: Latex, 7 pages including 2 .eps figure

Remarks on the multiplicity measure for e+e−e^{+}e^{-} annihilation

A recent proposal of the Lund group suggesting a multiplicity measure for $e^{+}e^{-}$ annihilation is analyzed. It is shown that the results obtained for the multiplicity distributions in full phase do not change if one removes a questionable assumption of exact localization of branching products in rapidity (thus avoiding troubles for small rapidity bins). The predicted asymptotic form of the distribution is shown to differ from the negative binomial distribution

Line-reversal symmetry breaking and the absorption corrections

The role of absorption corrections in the experimentally observed line-reversal symmetry breaking is discussed. The absorption parameters are estimated from experimental data and the quark model. It is shown that the absorption corrections cannot explain the experimentally observed effect

Line-reversal symmetry breaking and the quark model

The recently observed violation of exchange degeneracy rules for charge- and strangeness- exchange meson–baryon scattering is discussed in the framework of the quark model. It is shown that one can qualitatively describe the effect using the model in which q-q and q-$\overline{q}$ amplitudes have Regge form with exact exchange degeneracy and all observed deviations are caused by three-quark (q-qq) scattering

The fate of valence quarks in fragmentation processes

Simple quark models for hadronic fragmentation processes are shortly reviewed. It is pointed out that the existing models differ most significantly in the assumptions concerning involvement of valence quarks in the first stage of interaction. By investigating x-distributions of produced hadron pairs one can test these assumptions experimentally