http://nuclear.korea.ac.kr/~bhong/class/WhitePaper_PHENIX_RUN1-3.pdf

Formation of dense partonic matter in relativistic nucleus–nucleus collisions at RHIC: Experimental evaluation by the PHENIX Collaboration

The combination of the compactness of networks, featuring small diameters, and their complex architectures results in a variety of critical effects dramatically different from those in cooperative systems on lattices. In the last few years, important steps have been made toward understanding the qualitatively new critical phenomena in complex networks. The results, concepts, and methods of this rapidly developing field are reviewed. Two closely related classes of these critical phenomena are considered, namely, structural phase transitions in the network architectures and transitions in cooperative models on networks as substrates. Systems where a network and interacting agents on it influence each other are also discussed. A wide range of critical phenomena in equilibrium and growing networks including the birth of the giant connected component, percolation, $k$-core percolation, phenomena near epidemic thresholds, condensation transitions, critical phenomena in spin models placed on networks, synchronization, and self-organized criticality effects in interacting systems on networks are mentioned. Strong finite-size effects in these systems and open problems and perspectives are also discussed.

/pdf/critical-phenomena-in-complex-networks-4vxnv3f75f.pdf

Critical phenomena in complex networks

Topological charge changing transitions can induce chirality in the quark-gluon plasma by the axial anomaly. We study the equilibrium response of the quark-gluon plasma in such a situation to an external magnetic field. To mimic the effect of the topological charge changing transitions we will introduce a chiral chemical potential. We will show that an electromagnetic current is generated along the magnetic field. This is the chiral magnetic effect. We compute the magnitude of this current as a function of magnetic field, chirality, temperature, and baryon chemical potential.

Chiral magnetic effect

http://fig.if.usp.br/~mleite/PDF/0410022.pdf

The PHOBOS Perspective on Discoveries at RHIC

The effects of topological charge change in heavy ion collisions: “Event by event P and CP violation”

Although at asymptotically high temperatures the quark-gluon plasma (QGP) is a gas of weakly interacting quasiparticles (modulo long-range magnetism), and it has quite different properties at temperatures of the order of a few times the critical temperature $T=(1--3){T}_{c}$. As experiments and lattice simulations are now showing, in this region the QGP displays strong interactions between the constituents. In this paper we try to develop a theory of one of its consequences, namely, the properties of a large number of binary bound states, both hadronlike (colorless) and exotic (colored) bound pairs $gq$, $qq$, and $gg$. We evaluate their binding energies and zero-binding lines on the phase diagram and estimate their contribution to bulk thermodynamics (pressure). Their role in the transport properties (viscosity), emphasized in our previous paper, will be addressed elsewhere.

Toward a theory of binary bound states in the quark-gluon plasma

We argue that although at asymptotically high temperatures the quark-gluon plasma (QGP) in bulk behaves as a gas of weakly interacting quasiparticles (modulo long-range magnetism), it is different at temperatures up to few times the critical temperature ${T}_{c}$. In particular, we emphasize the role of several zero binding lines on the phase diagrams, below which $\overline{c}c$, light quarks, $gg$ as well as exotic $gq,qq$ bound states exist. Near these lines quasiparticle rescattering is enhanced dramatically, possibly explaining why heavy-ion collisions at the relativistic heavy-ion collider exhibit robust collective phenomena. Although in QCD the coupling constant in the QGP phase reaches only values $g\ensuremath{\sim}1$, using Maldacena duality one may study these phenomena in the strong coupling limit ${g}^{2}{N}_{c}⪡1$ in conformal gauge theories at finite temperature [e.g., $\mathcal{N}=4$ supersymmetric Yang-Mills (SUSY YM)]. Trapped atoms is another system which allows us to study strongly interacting matter, in the limit of infinite scattering length.

Rethinking the properties of the quark-gluon plasma at T c T 4 T c

Holography of radiation and jet quenching

We provide a method to study hadronic matter at finite density in the context of the Sakai-Sugimoto model. We introduce the baryon chemical potential through the external $U(1)_v$ in the induced (DBI plus CS) action on the D8-probe-brane, where baryons are skyrmions. Vector dominance is manifest at finite density. We derive the baryon density effect on the energy density, the dispersion relations of pion and vector mesons at large $N_c$. The energy density asymptotes to a constant at large density suggesting that dense matter at large $N_c$ freezes, with the pion velocity dropping to zero. Holographic dense matter enforces exactly the tenets of vector dominance, and screens efficiently vector mesons. At the freezing point the $\rho-\pi\pi$ coupling vanishes with a finite rho mass of about 20% its vacuum value.

https://www.arxiv.org/pdf/hep-th/0608046.pdf

Dense Hadronic Matter in Holographic QCD

We discuss a Pareto macroeconomy (a) in a closed system with fixed total wealth and (b) in an open system with average mean wealth, and compare our results to a similar analysis in a super-open system (c) with unbounded wealth [J.-P. Bouchaud and M. Mezard, Physica A 282, 536 (2000)]. Wealth condensation takes place in the social phase for closed and open economies, while it occurs in the liberal phase for super-open economies. In the first two cases, the condensation is related to a mechanism known from the balls-in-boxes model, while in the last case, to the nonintegrable tails of the Pareto distribution. For a closed macroeconomy in the social phase, we point to the emergence of a "corruption" phenomenon: a sizeable fraction of the total wealth is always amassed by a single individual.

https://arxiv.org/pdf/cond-mat/0101068.pdf

Ismail Zahed

Papers

Toward a theory of binary bound states in the quark-gluon plasma

Rethinking the properties of the quark-gluon plasma at T c T 4 T c

Holography of radiation and jet quenching

Dense Hadronic Matter in Holographic QCD

Wealth condensation in pareto macroeconomies.