Within the quark nugget model, dark matter particles may be represented by compact composite objects composed of a large number quarks or antiquarks. Due to strong interaction with visible matter, antiquark nuggets should manifest themselves in form rare atmospheric events on Earth. They produce ionized trails atmosphere similar meteor trails. There are, however, several features which allow on...

Measurements of heavy quark production in electron–positron collisions are used to analyse the strong interactions between quarks and anti-quarks. A scaling behaviour is observed in distributions of the rapidity change of D, B, and B mesons. From these distributions information is obtained on the hadron formation time, effective quark masses, and the potential between quark–antiquark pairs. Pre...

It is shown that Sudakov form factors for a colour dipole in a QCDinspired model of leptoproduction of vector mesons reduce the value of the cross section of the process by an order of magnitude. They suppress the large size quark-antiquark pairs and unequal sharing of energy among the components of the dipole. Some freedom in the choice of the model parameters is also discussed. The idea of in...

Exclusive charged B decays show an unexplained enhancement in low-lying channels which must be reversed in other channels to equalise charged and neutral lifetimes. One suggested explanation involves decay modes with excited mesons like the a1. The anomalous behaviour of decay modes of D and B mesons into final states containing the η and η mesons is discussed. 1 Systematics in charged and neut...

We discuss and compare different approaches to include gluon transverse momenta for heavy quark-antiquark pair production. The correlations in azimuthal angle and in heavy quark, heavy antiquark transverse momenta are studied in detail. The results are illustrated with the help of different unintegrated gluon distribution functons (UGDF) from the literature. We compare results obtained with ons...

Using adiabatic hybrid meson potentials calculated in the QCD string model, the mass spectrum of heavy hybrid mesons is calculated in Born-Oppenheimer approximation within the accuracy of 100 MeV. INTRODUCTION A phenomenon of valence glue is very interesting from theoretical point of view, since it is directly related to the phenomenon of confinement. It is well known that states consisting of ...

We study the quark-antiquark interaction in the large N limit of the superconformal field theory on D-3branes at a Calabi-Yau conical singularity. We compute the Wilson loop in the AdS5 × T 11 supergravity background for the SU(2N) × SU(2N) theory. We also calculate the Wilson loop for the Higgs phase where the gauge group is broken to SU(N) × SU(N) × SUD(N). This corresponds to a two center co...

In the world line representation of the fermionic effective action for QCD the interaction between Fermions and the gauge field is contained in the fermionic Wilson loop, namely the Wilson loop for a spinhalf particle. It is argued that a string representation of the fermionic Wilson loop can provide a link connecting QCD with a dual description of a meson as a quark and an antiquark connected ...