QCD and hybrid NBD on oscillating moments of multiplicity distributions in lepton- and hadron-initiated reactions

QCD predictions for moments of multiplicity distributions are compared with experimental data on e+e- collisions and their two-NBD fits. Moments of the multiplicity distribution in a two-NBD model for 1.8 TeV pp collisions are considered. Three-NBD model predictions and fits for pp at LHC energies are also discussed. Analytic expressions for moments of hybrid NBD are derived and used to get insight into jet parameters and multicomponent structure of the processes. Interpretation of observed correlations is proposed.Comment: 8 pages, no figures, Phys. Lett.

QCD and models on multiplicities in e+e−e^+e^- and ppˉp\bar p interactions

A brief survey of theoretical approaches to description of multiplicity distributions in high energy processes is given. It is argued that the multicomponent nature of these processes leads to some peculiar characteristics observed experimentally. Predictions for LHC energies are presented. It is shown that similarity of the energy dependence of average multiplicities in different reactions is not enough alone to suggest the universal mechanism of particle production in strongly-interacting systems. Other characteristics of multiplicity distributions depend on the nature of colliding partners.Comment: 16 pages, 11 figures, Phys. Atom. Nuc

A fresh look at eta2(1645), eta2(1870), eta2(2030) and f2(1910) in pbar-p -> eta + 3pizero

There is a large discrepancy between results of Crystal Barrel and WA102 for the branching ratio R = BR[eta2(1870)->a2(1320)pi]/ BR[eta2(1870)->f2(1270)eta]. An extensive re-analysis of the Crystal Barrel data redetermines branching ratios for decays of eta2(1870), eta2(1645), eta2(2030) and f2(1910). This re-analysis confirms a small value for R of 1.60+-0.39, inconsistent with the value 32.6+-12.6 of WA102. The likely origin of the discrepancy is that the WA102 data contain a strong f2(1910)->a2-pi signal as well as eta2(1870). There is strong evidence that the eta2(1870) has resonant phase variation. A peak in f2(1270)a0(980) confirms closely the parameters of the a2(2255) resonance observed previously. A peak in eta2(2030)-pi is interpreted naturally in terms of pi2(2245) with reduced errors for mass and width M=2285+-20(stat)+-25(syst) MeV, Gamma=250+-20(stat)+-25(syst) MeV.Comment: 25 pages, 13 figures; several major additions in final versio

Effective Lagrangian approach to the omega meson photoproduction near threshold

We apply the effective Lagrangian approach to investigate the role of the nucleon resonances in $\omega$ meson photoproduction at energies near the threshold. The resonant amplitudes are calculated from effective Lagrangians with the gamma NN* and omega NN* coupling constants fixed by the empirical helicity amplitudes and the vector meson dominance model. The contributions from the nucleon resonances are found to be significant in changing the differential cross sections in a wide interval of t and various spin observables.Comment: 25 pages, 10 figure

L'impact du contrat de travail sur la relation d'emploi en Chine

This research project consists of an analysis of the perceptions of young Chinese graduate employees on their psychological contract modeled by the transformations of market structures and a study on how the contractualization of their obligations and those of their employer modify the foundations of the relationship of employment which binds them reciprocally

Effets conjoints du contrat psychologique et du contrat de travail sur la relation d'emploi en Chine

Présentation du sujet de thèse lors d\u27une émission radiophonique de vulgarisation scientifique