Finite Temperature Phase Diagrams of Gauge Theories

We discuss finite temperature phase diagrams of SU(N) gauge theory with massless fermions as a function of the number of fermion flavors. Inside the conformal window we find a phase boundary separating two different conformal phases. Below the conformal window we find different phase structures depending on if the beta function of the theory has a first or higher order zero at the lower boundary of the conformal window. We also outline how the associated behaviors will help in distinguishing different types of theories using lattice simulations.Comment: 5 pages, 5 figure

Freezeout of resonances and nuclear fragments at RHIC

We quantify the conditions at which ``composites'', the resonances and bound states $d,He^3$ are produced at RHIC. Using Hubble-like model for late stages, one can analytically solve the rate equations and also calculate the relevant optical depth factors. We calculate also the modification of $\rho$ masse and width, and predict a radiacal shape change of $\sigma$.Comment: 6 pages, proccedings of 19th Winter Workshop on Nuclear Dynamics, Breckenridge, Colorado, February 200

QCD phases at high density and instantons

The talk is an introduction into diquark condensation phenomena which occur in QCD at high energy density. They are driven by instantons and instanton-antiinstanton pairs (or ``molecules''), which generate attraction in some qq channels. A number of phases is possible, with or without restoration of chiral symmetry: the work is not finished and we do not yet know which take place in real QCD. We also emphasize that specific diquark correlations play a significant role in baryon structure, in particular making that of a nucleon very different of a $\Delta$ (or other member of a decuplet). This ``small $N_c$'' scenario based on comparison to QCD with two colors is contrasted with the ``large $N_c$'' one.Comment: invited talk at "QCD at finite baryon density", Bielefeld, 199

On the Origin of the "Ridge" phenomenon induced by Jets in Heavy Ion Collisions

We argue that "ridge" in 2-particle correlation function associated with hard trigger at RHIC heavy ion collisions is naturally explained by an interrelation of jet quenching and hydrodynamical transverse flow. The excess particles forming the ridge are produced by QCD bremsstrahlung along the beam (and thus have wide rapidity distribution) and then boosted by transverse flow. Nontrivial correlation between directions of the jet and the radial flow is provided by jet quenching: our straightforward and basically parameter-independent calculation reproduces the angular shape, width and other properties of the "ridge"

Polymer Chains and Baryons in a Strongly Coupled Quark-Gluon Plasma

Recently there was a significant change of views on physical properties and underlying dynamics of Quark-Gluon Plasma at $T=170-350 MeV$, produced in heavy ion collisions at RHIC. Instead of being a gas of $q,g$ quasiparticles, a near-perfect liquid is observed. Also, precisely in this temperature interval, the interaction deduced from lattice studies is strong enough to support multiple binary bound states. This work is the first variational study of {\em multibody} bound states. We will consider: (i) ``polymer chains'' of the type $\bar q g g ..g q$; (ii) baryons $(qqq)$; (iii) closed (3-)chains of gluons $(ggg)$. We found that chains (i) form in exactly the same $T$ range as binary states, with the same binding {\em per bond}. The binding and $T$-range for diquarks, baryons and closed 3-chains are also established. We point out that the presence of chains, or possibly even a chain network, may drastically change the transport properties of matter, such as charm diffusion or jet energy loss. We further suggest that it seems to exist only for $T=(1-1.5)T_c$ and thus there may be a ``latent period'' for charm/jet quenching in RHIC collisions, while matter cools down to such $T$.Comment: New version submitted to Nuclear Physics A, with few changes in comments and figure

Nonperturbative contributions to the QCD pressure

We summarize the most important arguments why a perturbative description of finite-temperature QCD is unlikely to be possible and review various well-established approaches to deal with this problem. Then, using a recently proposed method, we investigate nonperturbative contributions to the QCD pressure and other observables (like energy, anomaly and bulk viscosity) obtained by imposing a functional cutoff at the Gribov horizon. Finally, we discuss how such contributions fit into the picture of consecutive effective theories, as proposed by Braaten and Nieto, and give an outline of the next steps necessary to improve this type of calculation.Comment: 15 pages, 13 figures, uses xcolor.sty; in v2 quality of some figures has been improved, discussion of other approaches has been extende