Angular distribution of energy in jets

The transverse momentum distribution of heavy C-even resonances produced in hadron collisions probes, according to QCD, the spatial spread of color charge in gluons. An all-orders calculation of the effective doubly logarithmic gluon form factor is supported by recent data on χ (3.5) production. We predict a very wide p_t distribution of C-even b$\text{b}$ resonances associated with ?.     

On the sensitivity of the inclusive distributions in parton jets to the coherence effects in QCD gluon cascades

The KNO multiplicity distributions and properties of two-particle correlations in QCD jets are considered in the framework of the perturbative approach accounting for effects of the coherence in the soft gluon bremsstrahlung.     

On the transverse momentum distribution of massive lepton pairs

The experimentally measured q_t distributions of massive lepton pairs produced in hadron collisions are compared with the predictions of QCD [1]. We demonstrate that a fair agreement may be achieved without the use of large transverse momenta of the constitunt quarks - owing to a specific double-logarithmic form factor which manifests itself in this process. A prediction for the q_t distribution in weak intermediate boson production is also given.     

Double logs of perturbative QCD for parton jets and soft hadron spectra

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.     

Revisiting non-perturbative effects in the jet broadenings

We show that taking into account the interplay between perturbative and non-perturbative effects, the power-suppressed shift to the broadening distributions becomes B dependent, and the non-perturbative contribution to the mean values becomes proportional to . The new theoretical treatment greatly improves the consistency of the phenomenology with the notion of the universality of confinement effects in jet shapes.This work was supported in part by the EU Fourth Framework Programme ‘Training and Mobility of Researchers’, Network ‘Quantum Chromodynamics and the Deep Structure of Elementary Particles’, contract FMRX-CT98-0194 (DG 12-MIHT).