Multiplicity difference between heavy- and light-quark jets revisited

The perturbative QCD approach to multiparticle production predicts a characteristic suppression of particle multiplicity in a heavy-quark jet as compared to a light-quark jet. In the modified leading logarithmic approximation (MLLA) the multiplicity difference between heavy- and light-quark jets is derived in terms of a few other experimentally measured quantities. The earlier prediction for b-quarks needs revision in the light of new experimental results and the improvement in the understanding of the experimental data. We now find . The updated MLLA results on and are compared with the present data from e ⁺ e^- annihilation. Their expected energy independence is confirmed within the energy range between 29 and 200 GeV; the absolute values are now in better agreement with experiment than in the previous analysis, and the remaining difference can be attributed largely to next-to-MLLA contributions, an important subset of which are identified and evaluated. Arrival of the final proofs: 22 November 2005     

Nucleation kinetics,micro-crystallization and surface morphology studies of the nonlinear optical single-crystal l-lysinium trifluoroacetate

The organic nonlinear optical crystal of amino-carboxyl acid family, l-lysinium trifluoroacetate (abbreviated as LLTF) was successfully grown from its aqueous solution by the temperature-lowering technique. Its growth morphology was investigated based on the X-ray single-crystal diffraction data and the growth habits were studied using the micro-crystallization method. The metastable zonewidth and induction period were determined for the aqueous solution growth of LLTF. The surface free energy values were calculated from the experimental data. Nucleation kinetics and fundamental growth parameters such as critical radius, critical free energy and volume free energy change were also evaluated. Crystals of LLTF were obtained by the optimized nucleation parameters.     

pQCD physics of multiparton interactions

We study production of two pairs of jets in hadron–hadron collisions in view of extracting contribution of double hard interactions of three and four partons (3→4, 4→4). Such interactions, in spite of being power suppressed at the level of the total cross section, become comparable with the standard hard collisions of two partons, 2→4, in the back-to-back kinematics when the transverse momentum imbalances of two pairing jets are relatively small.     

Parton dynamics, 30 years later

A review of the basics of the QCD parton evolution picture is given with an emphasis on recent findings that reveal intrinsic beauty, and hint at hidden potential simplicity, of the perturbative quark-gluon dynamics. The text was submitted by the authors in English.     

Coherent effects in the perturbative QCD parton jets

The influence of coherence in a soft parton bremsstrahlung on hadron spectra in jets is discussed. We present a simple functional method for calculation of different inclusive parton distributions in the “plateau” region. Inclusive parton cross sections, spectra, multiplicities, energy and angular correlations, etc. are derived in the Double Logarithmic approximation.     

Hump-backed QCD plateau in hadron spectra

New data on inclusive energy distribution of hadrons from quark jets ine ⁺ e ^? annihilation are shown to agree with the quantitative predictions of perturbative QCD, supporting the hypothesis of local parton-hadron duality.