One of the key objectives of the COMPASS experiment at CERN is the determination of the gluon contribution to the nucleon spin. The gluon polarization is measured via photon-gluon fusion in deep-inelastic scattering of 160 GeV/c polarized muons on a polarized LiD solid-state target. Photon-gluon fusion is tagged by the observation of charmed mesons or the production of hadron pairs with large t...

We argue that multiparticle production in high energy hadron and nuclear collisions can be considered as proceeding through the production of gluons in the background classical field. In this approach we derive the gluon spectrum immediately after the collision and find that at high energies it is parametrically enhanced by ln(1/x) with respect to the quasiclassical result (x is the Bjorken var...

We investigate photo-production of vector mesons J/Psi and Psi(2s), based on both HERA LHC data, using 2 fits unintegrated gluon distributions. The latter are subject to non-linear Balitsky-Kovchegov evolution (Kutak-Sapeta gluon; KS) linear next-to-leading order Balitsky-Kuraev-Fadin-Lipatov (Hentschinski-Sabio Vera-Salas; HSS gluon) respectively. Apart from extending previous studies the case...

The Kugo–Ojima confinement criterion and its relation to the infrared behaviour of the gluon and ghost propagators in Landau gauge QCD are reviewed. The realization of this confinement criterion (which in Landau gauge relates to Zwanziger's horizon condition) results from quite general properties of the ghost Dyson– Schwinger equation. The numerical solutions for the gluon and ghost propagators...

Kazuhisa Amemiya and Hideo Suganuma Research Center for Nuclear Physics (RCNP), Osaka University Mihogaoka 10-1, Ibaraki, Osaka 567-0047, Japan E-mail: [email protected] We study the origin of the abelian dominance in the maximally abelian (MA) gauge for the long-distance physics in terms of the interaction range mediated by gluons. In the MA gauge, diagonal gluon components behave as ...

The mixed quark-gluon condensate is another chiral order parameter in QCD, which plays an important role in the application of QCD sum rules. In this letter, we study the properties of quark-gluon mixed condensate at finite temperature and quark chemical potential in the framework of global color symmetry model. Using an infrareddominant model gluon two-point function, we find that the behavior...