Edge states for topological insulators in two dimensions and their Luttinger-like liquids
Topological insulators in three spatial dimensions are known to possess a precise bulk-boundary correspondence, in that there is a one-to-one correspondence between the five classes characterized by bulk topological invariants and Dirac Hamiltonians on the boundary with symmetry protected zero modes. This holographic characterization of topological insulators is studied in two dimensions. Dirac Hamiltonians on the one-dimensional edge are classified according to the discrete symmetries of time reversal, particle hole, and chirality, extending a previous classification in two dimensions. We find 17 inequivalent classes, of which 11 have protected zero modes. Although bulk topological invariants are thus far known for only five of these classes, we conjecture that the additional six describe edge states of new classes of topological insulators. The effects of interactions in two dimensions are also studied. We show that all interactions that preserve the symmetry are exactly marginal, i.e., preserve the gaplessness. This leads to a description of the distinct variations of Luttinger liquids that can be realized on the edge.

title: Logarithmic Yangians in WZW Models
abstract: A new action of the Yangians in the WZW models is displayed. Its structure is generic and level-independent. This Yangian is the natural extension at the conformal point of the one unraveled in massive theories with current algebras. Hopefully, this new symmetry of WZW models will lead to a deeper understanding of the integrable structure of conformal field theories and their deformations.

title: Anomalous scaling in the N-point functions of a passive scalar.
abstract: A recent analysis of the 4-point correlation function of the passive scalar advected by a time-decorrelated random flow is extended to the N-point case. It is shown that all stationary-state inertial-range correlations are dominated by homogeneous zero modes of singular operators describing their evolution. We compute analytically the zero modes governing the N-point structure functions and the anomalous dimensions corresponding to them to the linear order in the scaling exponent of the 2-point function of the advecting velocity field. The implications of these calculations for the dissipation correlations are discussed.

title: An Introduction to Yangian Symmetries
abstract: We review some aspects of the quantum Yangians as symmetry algebras of two-dimensional quantum field theories. The plan of these notes is the following: 
 
1 
 
The classical Heisenberg model: 
 
 
 
 
 
 
 
 
 
Non-Abelian symmetries; 
 
 
The generators of the symmetries and the semi-classical Yangians; 
 
 
An alternative presentation of the semi-classical Yangians; 
 
 
Digression on Poisson-Lie groups. 
 
 
Non-Abelian symmetries and the quantum Yangians; 
 
 
The transfer matrix and an alternative presentation of the Yangians; 
 
 
Digression on the double Yangians. 
 
 
 
 
 
2 
 
The quantum Heisenberg chain: 
 
 
 
 
 
 
 
 
 
Non-Abelian symmetries and the quantum Yangians; 
 
 
The transfer matrix and an alternative presentation of the Yangians; 
 
 
Digression on the double Yangians.

title: Spin-Charge Separation and the Spin Quantum Hall Effect
abstract: We use quantum field theory methods to study the network model for the spin quantum hall transition. When the couplings are fine tuned in a certain way, the spin and charge degrees of freedom, corresponding to the su-percurrent algebras su(2) 0 and osp(2|2) −2 respectively, completely decouple. This simpler theory is exactly solvable and some critical exponents are computed and shown to agree with the recent predictions based on percolation. The general network model is shown to be in a different universality class by identifying the attractive direction of the renormalization group flow.

title: On Root Multiplicities of Some Hyperbolic Kac–Moody Algebras
abstract: Using the coset construction, we compute the root multiplicities at level-3 for some hyperbolic Kac–Moody algebras including the basic hyperbolic extension of A11 and E10.

title: Electron acceleration in the plasma beat‐wave experiment at Ecole Polytechnique
abstract: Recent results of a plasma Beat‐Wave acceleration experiment are presented. A plasma wave is created in a D2 plasma by the beating of a Nd‐YAG and a Nd‐YLF laser pulse. Electrons at energies of 3 MeV are injected into the plasma. Several hundred electrons accelerated up to 3.7 MeV are observed in correlation with a Thomson scattering signal. The dependence of the electron acceleration on the plasma density demonstrates the beat‐wave origin of the acceleration mechanism. This paper is mainly devoted to the description of the experimental set‐up. A particular attention was paid to efficient electron injection and to background noise suppression. A preliminary analysis of the results is also presented.

title: Branching fractions in $B \to \phi$ h and search for direct CP violation in $B^\pm \to \phi K^\pm$

title: Observation of time-reversal violation in the B0 meson system.
abstract: Although CP violation in the B meson system has been well established by the B factories, there has been no direct observation of time-reversal violation. The decays of entangled neutral B mesons into definite flavor states (B(0) or B(0)), and J/ψK(L)(0) or ccK(S)(0) final states (referred to as B(+) or B(-)), allow comparisons between the probabilities of four pairs of T-conjugated transitions, for example, B(0) → B(-) and B(-) → B(0), as a function of the time difference between the two B decays. Using 468 × 10(6) BB pairs produced in Υ(4S) decays collected by the BABAR detector at SLAC, we measure T-violating parameters in the time evolution of neutral B mesons, yielding ΔS(T)(+) = -1.37 ± 0.14(stat) ± 0.06(syst) and ΔS(T)(-) = 1.17 ± 0.18(stat) ± 0.11(syst). These nonzero results represent the first direct observation of T violation through the exchange of initial and final states in transitions that can only be connected by a T-symmetry transformation.

title: Search for dark matter at high-power laser facilities : flawed luminosity calculations in QPS -- Quasi parallel scattering
abstract: I point the erroneous use, in several papers published recently, of the well known expression for the luminosity of the head-on collision of two particle bunches, in a QPS -- Quasi parallel scattering -- configuration, in which the two beams are co-propagating, and the collision of individual particles takes place at a small angle wrt co-propagation.

title: Simultaneous Measurement of the $B^0$ Meson Lifetime and Mixing Frequency with $B^0 \rightarrow D^{*-}\ell^+\nu_\ell$ Decays
abstract: We measure the B0 lifetime tau_B0 and the B-Bbar oscillation frequency Deltam_d with a sample of approximately 14,000 exclusively reconstructed B0 -> D*- l+ nu_l signal events, selected from 23 million B-Bbar pairs recorded at the Upsilon(4S) resonance with the BABAR detector at the Stanford Linear Accelerator Center. The b-quark flavor of the other B at the time of decay and its decay position are determined inclusively. The lifetime and oscillation frequency are measured simultaneously with an unbinned maximum-likelihood fit that uses, for each event, the measured difference in B decay times (Delta-t), the calculated uncertainty on Delta-t, the signal and background probabilities, and b-quark tagging information for the other B. The preliminary results are tau_B0 = (1.523 +0.024 -0.023 (stat) +/- 0.022 (syst)) ps and Deltam_d = (0.492 +/- 0.018 (stat) +/- 0.013 (syst)) ps^-1. The statistical correlation coefficient between tau_B0 and Deltam_d is -0.22.