989 research outputs found

    A Color Mutation Model of Soft Interaction in High Energy Hadronic Collisions

    Get PDF
    A comprehensive model, called ECOMB, is proposed to describe multiparticle production by soft interaction. It incorporates the eikonal formalism, parton model, color mutation, branching and recombination. The physics is conceptually opposite to the dynamics that underlies the fragmentation of a string. The partons are present initially in a hadronic collision; they form a single, large, color-neutral cluster until color mutation of the quarks leads to a fission of the cluster into two color-neutral subclusters. The mutation and branching processes continue until only qqˉq\bar q pairs are left in each small cluster. The model contains self-similar dynamics and exhibits scaling behavior in the factorial moments. It can satisfactorily reproduce the intermittency data that no other model has been able to fit.Comment: 24 pages including 11 figures in revtex epsf styl

    Nonextensive Statistics and Multiplicity Distribution in Hadronic Collisions

    Full text link
    The multiplicity distribution of particles in relativistic gases is studied in terms of Tsallis' nonextensive statistics. For an entropic index q>1 the multiplicity distribution is wider than the Poisson distribution with the same average number of particles, being similar to the negative binomial distribution commonly used in phenomenological analysis of hadron production in high-energy collisions

    Transesterification of PHA to Oligomers Covalently Bonded with (Bio)Active Compounds Containing Either Carboxyl or Hydroxyl Functionalities

    Get PDF
    © 2015 The Authors. Published by Public Library of Science. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1371/journal.pone.0120149This manuscript presents the synthesis and structural characterisation of novel biodegradable polymeric controlled-release systems of pesticides with potentially higher resistance to weather conditions in comparison to conventional forms of pesticides. Two methods for the preparation of pesticide-oligomer conjugates using the transesterification reaction were developed. The first method of obtaining conjugates, which consist of bioactive compounds with the carboxyl group and polyhydroxyalkanoates (PHAs) oligomers, is "one-pot" transesterification. In the second method, conjugates of bioactive compounds with hydroxyl group and polyhydroxyalkanoates oligomers were obtained in two-step method, through cyclic poly(3-hydroxybutyrate) oligomers. The obtained pesticide-PHA conjugates were comprehensively characterised using GPC, 1H NMR and mass spectrometry techniques. The structural characterisation of the obtained products at the molecular level with the aid of mass spectrometry confirmed that both of the synthetic strategies employed led to the formation of conjugates in which selected pesticides were covalently bonded to PHA oligomers via a hydrolysable ester bond

    Scenarios for multiplicity distributions in pp collisions in the TeV energy region

    Full text link
    Possible scenarios based on available experimental data and phenomenological knowledge of the GeV energy region are extended to the TeV energy region in the framework of the weighted superposition mechanism of soft and semi-hard events. KNO scaling violations, forward-backward multiplicity correlations, Hq vs. q oscillations and shoulder structures are discussed.Comment: 10 pages, 10 figures, talk given at "Focus on Multiplicity" (Bari, Italy, June 2004

    Hadronic sizes and observables in high-energy scattering

    Get PDF
    The functional dependence of the high-energy observables of total cross section and slope parameter on the sizes of the colliding hadrons predicted by the model of the stochastic vacuum and the corresponding relations used in the geometric model of Povh and H\"ufner are confronted with the experimental data. The existence of a universal term in the expression for the slope, due purely to vacuum effects, independent of the energy and of the particular hadronic system, is investigated. Accounting for the two independent correlation functions of the QCD vacuum, we improve the simple and consistent description given by the model of the stochastic vacuum to the high-energy pp and pbar-p data, with a new determination of parameters of non-perturbative QCD. The increase of the hadronic radii with the energy accounts for the energy dependence of the observables.Comment: Latex, using Revtex.style . 2 ps figures. To be published in Physical Review D , July 199

    Charged rho meson production in neutrino-induced reactions at E_nu = 10 GeV

    Full text link
    The neutrinoproduction of charged ρ\rho mesons on nuclei and nucleons is investigated for the first time at moderate energies ( \approx 10 GeV), using the date obtained with SKAT bubble chamber. No strong nuclear effects are observed in ρ+\rho^+ and ρ\rho^- production. The fractions of charged and neutral pions originating from ρ\rho decays are obtained and compared with higher energy data. From analysis of the obtained and available data on ρ+\rho^+ and K+K^{*+}(892) neutrinoproduction, the strangeness suppression factor in the quark string fragmentation is extracted: λs=0.18±0.03\lambda_s = 0.18\pm0.03. Estimations are obtained for cross sections of quasiexclusive single ρ+\rho^+ and coherent ρ+\rho^+ neutrinoproduction on nuclei. The estimated coherent cross section σρ+coh\sigma_{\rho^+}^{coh} = (0.29±0.16)1038\pm0.16)\cdot 10^{-38} cm2^2 is compatible with theoretical predictions.Comment: 7 pages, 6 figure

    Next-to-Leading Order Constituent Quark Structure and Hadronic Structure Functions

    Get PDF
    We calculate the partonic structure of a constituent quark in the Next-to-Leading Order framework. The structure of any hadron can be obtained thereafter using a convolution method. Such a procedure is used to generate the structure function of proton and pion in NLO, neglecting certain corrections to ΛQCD\Lambda_{QCD}. It is shown that while the constituent quark structure is generated purely perturbatively and accounts for the most part of the hadronic structure, there is a few percent contributions coming from the nonperturbative sector in the hadronic structure. This contribution plays the key role in explaining the SU(2) symmetry breaking of the nucleon sea and the observed violation of Gottfried sum rule. These effects are calculated. We obtained an Excellent agreement with the experimental data in a wide range of x=[106,1]x=[10^{-6}, 1] and Q2=[0.5,5000]Q^{2}=[0.5, 5000] GeV2GeV^{2} for the proton structure function. We have also calculated Pion structure and compared it with the existing data. Again, the model calculations agree rather well with the data from experiment.Comment: 32 pages,10 figures, Accepted to publish in Phys. Rev.
    corecore