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We describe how the formalism of Field Theory can be applied in the study of linear polymers. Fractional fermion number due to topological backgrounds is used to probe for fermion bound states associated to deformations of the linear lattice. A transition is exhibited and its phenomenological consequences are explored.

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In SU(3)-flavor Skyrme model, three different ways of defining the \(N_c \to \infty \) limit are proposed. Mass splittings and magnetic moments are calculated in this limit. The calculations show importance of \(1/N_c\) corrections.

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A scheme for numerical calculation of certain values in the Chiral Bag Model, obtained independently by means of asymptotic expansions, is presented. The method was employed in the case of the moments of the baryon number density originating from the vacuum polarization, serving as a cross check for the correctness of analytical calculations.

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We investigate influence of temperature effects on evolution of a scalar field in the new inflationary model of the Universe. We study a simple model of a potential and show that temperature effects only slightly influence the duration of the inflationary period and the amplitude of density perturbations.

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We report on a theoretical investigation of parton and hadron multiplicity distributions produced by quark–antiquark and gluon–gluon systems at centre-of-mass energies from 22 GeV to 2 TeV, on the basis of the Lund Shower Model, which is the Monte Carlo parton-shower and hadronization model accounting best for the available \(e^+e^-\) annihilation data. Both classes of distributions are studied for full phase space and central rapidity windows. They are found to have negative binomial properties analogous to those observed in many experiments. We also find a simple relation between the partonic and hadronic distributions; it can be linked with the concepts of preconfinement and local parton–hadron duality. At partonic level, the results suggest a simple interpretation in terms of independent emission of “bremsstrahlung gluon jets” having geometric multiplicity distribution.

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Since 1984, remarkable regularities related to negative binomial (NE) properties have been found in the experimental multiplicity distributions of \(e^+e^-\) annihilation, leptoproduction and soft hadronic collisions at high energies. From a “Monte Carlo experiment” based on the Lund version of the QCD parton shower model for \(e^+e^-\) annihilation, we have recently shown that the same NB regularities are predicted for multiparticle production by quark–antiquark and gluon–gluon systems up to 2 TeV, not only for the final hadrons but also for the final partons before hadronization. In addition, we have found an approximate, but physically intuitive, description of the parton shower (independent emission of selfsimilar gluon jets) and of the hadronization (a specific form of local parton–hadron duality). Motivated by the observed universality of the NB regularities, we now extend our approximate parton shower description to leptoproduction and soft hadronic collisions. We show that it provides a method of calculating partonic multiplicity distributions from the experimental hadronic ones, and we give applications to muon–proton and proton–(anti)proton collisions. In the soft hadronic case, we propose a dynamical justification for a perturbative parton shower description and we indicate consequences for ultra-relativistic nuclear collisions and the problem of quark–gluon plasma formation.

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We study how the plasma production in ultrarelativistic heavy-ion collisions depends on the radius of the initial color flux tubes.

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Excitation functions (\(E_{cm} = 13.4\)–16.8 MeV) and angular distributions (\(E_{cm} = 13.8\) and 16.38 MeV) of \(^{12}\)C(\(^{13}\)C, \(^8\)Be)\(^{17}\)O reaction have been measured and analysed by means of statistical and direct reaction mechanism models. The direct reaction analysis includes one and two step processes. For this purpose measurements and analyses were also performed for the reactions \(^{12}\)C(\(^{13}\)C, \(^9\)Be)\(^{16}\)O (at \(E_{cm} = 13.8\) MeV) and \(^{16}\)O(\(^9\)Be, \(^8\)Be)\(^{17}\)O (at \(E_{cm} = 10.3\) and 12.8 MeV). The results were used to estimate the magnitude of the direct two-step (n-\(^4\)He) and (\(^4\)He-n) transfers in the \(^{12}\)C(\(^{13}\)C, \(^8\)Be)\(^7\)O reaction. These two-step transfers as well as the compound nucleus mechanism, account only for approximately 10% of the experimental cross sections. Thus a dominance of the one-step five-nucleon transfer is concluded. Estimates of the direct \(^5\)He-cluster transfer describe the data qualitatively.