Instanton-Induced Polarization in Exclusive Hyperon Photoproduction

It is shown that instantons can provide an explanation of the strong polarization transfer observed in exclusive hyperon photoproduction at JLab.Comment: 4 pages,1 figure, version to appear in Phys.Rev.D, Brief Repor

Glueball-Induced Partonic Energy Loss in Quark-Gluon Plasma

We discuss the energy loss of energetic parton jets in quark-gluon plasma above the deconfinement temperature $T_c$ by the interaction with scalar and pseudoscalar glueballs. It is shown that the loss by this mechanism is quite important and may play the important role of the observed jet-quenching.Comment: 5 pages, 3 figures, version to appear in Phys.Rev.

The Physics of Glueballs

Glueballs are particles whose valence degrees of freedom are gluons and therefore in their description the gauge field plays a dominant role. We review recent results in the physics of glueballs with the aim set on phenomenology and discuss the possibility of finding them in conventional hadronic experiments and in the Quark Gluon Plasma. In order to describe their properties we resort to a variety of theoretical treatments which include, lattice QCD, constituent models, AdS/QCD methods, and QCD sum rules. The review is supposed to be an informed guide to the literature. Therefore, we do not discuss in detail technical developments but refer the reader to the appropriate references.Comment: Invited review for Int. J. Mod. Phys. E, 32 pages, 12 figures, 8 table