118156864
Fermi Hyper-Netted Chain Theory on a Lattice: The Hubbard Model
We review a new lattice version of Fermi Hyper-Netted Chain method for the study of strongly interacting electrons. The ordinary paramagnetic and the spin density wave functions have been correlated with Jastrow-type and e — d correlations, and the corresponding FHNC equations for the pair distribution function, the one body density matrix and the staggered magnetization are discussed. Results for the 1D chain and 2D square lattice models are presented and compared with the available results obtained within Quantum Monte Carlo, variational Monte Carlo and exact diagonalization of a 4x4 Hubbard cluster. Particularly interesting are the strong effects of e — d correlations on E/Nt and on the momentum distribution as well as antiferromagnetic behavior away from half filling found in our FHNC calculations in agreement with other studies.
43360814
Critical Behavior of the S=3/2 Antiferromagnetic Heisenberg Chain.
Using the density-matrix renormalization-group technique we study the long-wavelength properties of the spin S=3/2 nearest-neighbor Heisenberg chain. We obtain an accurate value for the spin velocity v=3.8+- 0.02, in agreement with experiment. Our results show conclusively that the model belongs to the same universality class as the S=1/2 Heisenberg chain, with a conformal central charge c=1 and critical exponent eta=1
121898607
HNC Theory for Shadow Wave Functions
The hyper-netted-chain theory is applied to the study of strongly interacting Bose and Fermi systems described by the shadow-correlated wave functions. A new class of shadow wave functions is also proposed which, in spite of their greater generality, requires a much simpler HNC scheme to compute distribution functions, density matrices and the energy expectation value. Moreover, HNC-theory allows for a full optimization of the correlations functions, particularly in the case of this new class of extended shadow wavefunctions. Possible applications of the shadow wave functions to the study of the Fractional Quantum Hall effect are also discussed.
122672111
High PT probes of nuclear collisions
Abstract Jet quenching in high energy nuclear collisions is shown to provide new information on the energy loss mechanisms in dense matter near the quark-gluon plasma transition. In addition it is shown that A dependence of the inclusive p T spectra in p + A provides novel constraints on gluon shadowing in nuclei.
119023635
Dynamics of giant-gravitons in the LLM geometry and the fractional quantum Hall effect
Abstract The LLM's 1 / 2 BPS solutions of IIB supergravity are known to be closely related to the integer quantum Hall droplets with filling factor ν = 1 , and the giant gravitons in the LLM geometry behave like the quasi-holes in those droplets. In this paper we consider how the fractional quantum Hall effect may arise in this context, by studying the dynamics of giant graviton probes in a special LLM geometry, the AdS 5 × S 5 background, that corresponds to a circular droplet. The giant gravitons we study are D3-branes wrapping on a 3-sphere in S 5 . Their low energy world-volume theory, truncated to the 1 / 2 BPS sector, is shown to be described by a Chern–Simons finite-matrix model. We demonstrate that these giant gravitons may condense at right density further into fractional quantum Hall fluid due to the repulsive interaction in the model, giving rise to the new states in IIB string theory. Some features of the novel physics of these new states are discussed.
119481484
Open spin chain and open spinning string
In this Letter, we study the open spinning strings and their SYM duals. A new class of folded open spinning strings is found. At planar one-loop level in SYM, by solving the thermodynamic limit of the Bethe ansatz equations for an integrable open spin chain, we find good agreement with string theory predictions for energies of both circular and folded two-spin solutions. A universal relation between the open and closed spinning strings is verified in the spin chain approach.
119479056
Integrable spin chain and operator mixing in N=1,2 supersymmetric theories
Abstract We study operator mixing, due to planar one-loop corrections, for composite operators in D =4 supersymmetric theories. We present some N =1,2 Yang–Mills and Wess–Zumino models, in which the planar one-loop anomalous dimension matrix in the sector of holomorphic scalars is identified with the Hamiltonian of an integrable quantum spin chain with SU (3) or SU (2) symmetry, even if the theory is away from the conformal points. This points to a more universal origin of the integrable structure beyond superconformal symmetry. We also emphasize the role of the superpotential in the appearance of the integrable structure. The computations of operator mixing in our examples by solving Bethe ansatz equations show some new features absent in N =4 SYM.
18838442
Approach to Parton Equilibration
Abstract Perturbative QCD-based models of parton production and equilibration in ultrarelativistic heavy ion collisions are reviewed with an emphasis on the treatment of quantum interference effects. Uncertainties in the initial parton production and their effects on later parton equilibration are considered. Probes of early parton dynamics are also discussed.