In Leading Order (LO) prompt photons originating in the hard interaction between two partons are produced mainly via quark-gluon Compton scattering (qg → qγ) or quark–anti-quark annihilation (qq̄ → gγ). Studies of direct photons with large transverse momenta, pγT , provide precision tests of perturbative QCD (pQCD) as well as information on the distribution of partons within protons, particularl...

Meson masses within the model of induced nonlocal quark currents. Abstract The model of induced quark currents formulated in our recent paper (Phys. Rev. D51, 174) is developed. The model being a kind of nonlocal extension of the bosonization procedure is based on the hypothesis that the QCD vacuum is realized by the (anti-)self-dual homogeneous gluon field. This vacuum field provides the analy...

At sufficiently high baryon densities, the physics of a dense quark-gluon plasma may be investigated through the tools of perturbative QCD. This approach has recently been successfully applied to the study of color superconductivity, where the dominant di-quark pairing interaction arises from one gluon exchange. Screening in the plasma leads to novel behaviour, including a remarkable non-BCS sc...

In QCD, the Schwinger mechanism endows gluons with an effective mass through dynamical formation of massless bound-state poles that are longitudinally coupled. The presence these affects profoundly infrared properties interaction vertices, inducing crucial modifications to their fundamental Ward identities. Within this general framework, we present a detailed derivation non-Abelian identity obe...

We study charmonium production in hadron-nucleus collisions through the intermediate next-to-leading Fock space component |(c¯ c) 8 g, formed by a colour octet c¯ c pair and a gluon. We estimate the size of this state and show that its interaction with nucleons accounts for the observed charmonium suppression in nuclear interactions.

Final-state interaction phase difference in J/ψ → ρη and ωη decays Abstract It is shown that the study of the ω − ρ 0 interference pattern in the J/ψ → (ρ 0 + ω)η → π + π − η decay provides the evidence for the large (nearly 90 •) relative phase between the one-photon and the three-gluon decay amplitudes.

In this contribution I concentrate on the recent results from experiment E864 at the BNL-AGS. E864’s recent analysis have achieved sensitivities of approximately 3 × 10 per 10% central interaction for the production of charged strangelets and the first analysis for neutral strangelets is near completion. I put the results in the context of coalescence and quark gluon plasma strangelet productio...

A system of two static quarks, at fixed distances r, and two light quarks is studied on an anisotropic lattice. Excitations by operators emphasizing quark or gluon degrees of freedom are examined. The maximum entropy method is applied in the spectral analysis. These simulations ultimately aim at learning about mechanisms of hadronic interaction.

We present a self consistent approach to Coulomb gauge Hamiltonian QCD which allows one to relate single gluon spectral properties to the long range behavior of the confining interaction. Nonperturbative renormalization is discussed. The numerical results are in good agreement with phenomenological and lattice forms of the static potential. Typeset using REVTEX 1

The detection of high energy cosmic ray interactions at the medium depth underground is studied. Detected high energy muons carry information about the initial interaction. This might reveal the effects resulting from creation of quark gluon plasma at high energy interactions of iron nuclei contained in cosmic rays with the air. submitted to Astroparticle Physics ∗) e-mail:[email protected]