The plasma beat-wave acceleration experiment at Ecole Polytechnique
We present an experiment for demonstrating the principle of plasma beat-wave acceleration. The beating of two Nd-laser pulses creates a relativistic plasma wave in a deuterium plasma. Electrons at an energy of 3 MeV are injected into the plasma. We observe several hundred electrons accelerated up to 3.7 MeV. This paper is mainly devoted to the description of the experimental apparatus. In the design of the apparatus, we gave particular attention to efficient electron injection and to background noise suppression. We present also some preliminary results of electron acceleration experiments.

title: Measurement of the CKM matrix element $|V_{ub}|$ with $B \to \rho e \nu$ decays

title: Improved Measurement of CP Violation in Neutral B Decays to c cs

title: Operation of the Cherenkov detector DIRC of BABAR at high luminosity
abstract: The DIRC (acronym for Detection of Internally Reflected Cherenkov (light)) is the ring imaging Cherenkov detector of the BABAR detector at the PEP-II ring of SLAC. It provides the identification of pions, kaons and protons for momenta up to 4 GeV/c with high efficiency. This is needed to reconstruct CP-violating B-decay final states and to provide B-meson flavour tagging for time dependent asymmetry measurements. The DIRC radiators consists of long rectangular bars made of synthetic fused silica and the photon detector is a water tank equipped with an array of 10.752 conventional photomultipliers. At the end of the year 2000 BABAR has recorded about 22 million B~B pairs reaching the design luminosity of L=3/spl middot/10/sup 33//cm/sup 2/s. The ability to keep the beam background level low at highest collision rates and the long term reliability of the DIRC components during continuous data taking are requirements of BABAR to accomplish its physics program.

title: Branching fraction for $B^{+} \to \pi^0 \ell^{+} \nu$, measured in $\upsilon_{4S} \to B \bar{B}$ events tagged by $B^{-} \to D^0 \ell^{-}$ anti-v ($X$) decays

title: Measurements of branching fractions and CP-violating asymmetries in B-meson decays to the charmless two-body states K0 pi+, anti-K0 K+, and K0 anti-K0

title: Strong–weak coupling duality in anisotropic current interactions
abstract: The recently proposed all orders β function for current interactions in two dimensions is further investigated. By using a strong–weak coupling duality of the β function, and some added topology of the space of couplings we are able to extend the flows to arbitrarily large or small scales. Using a nontrivial RG invariant we are able to identify sine-Gordon, sinh-Gordon and Kosterlitz–Thouless phases. We also find an additional phase with cyclic or roaming RG trajectories.

title: The sine-Gordon solitons as an N-body problem
abstract: We consider the N -soliton solutions in the sine-Gordon model as an N -body problem. This leads to a relativistic generalization of the Calogero model first introduced by Ruijsenaars. We show that the fundamental Poisson bracket of the Lax matrix is quadratic, and the r -matrix is a dynamical one. This is in contrast to the Calogero model where the fundamental Poisson bracket of the Lax matrix is linear.

title: Dressing transformations and the origin of the quantum group symmetries
abstract: We consider the groups of dressing transformations in the Toda theories. We show how the splitting of the chiralities disentangles its action. It thus provides a very simple example illustrating the Lie Poisson structures of these groups. After quantization, dressing transformations generate quantum group symmetries.

title: Differential equations for sine-Gordon correlation functions at the free fermion point
abstract: We demonstrate that for the sine-Gordon theory at the free fermion point, the 2-point correlation functions of the fields eiαΦ for 0 < α < 1 can be parameterized in terms of a solution to the sinh-Gordon equation. This result is derived by summing over intermediate multiparticle states and using the form factors to express this as a Fredholm determinant. The proof of the differential equations relies on a Z2 graded multiplication law satisfied by the integral operators of the Fredholm determinant. Using this methodology, we give a new proof of the differential equations which govern the spin and disorder field correlations in the Ising model.

title: Form factors, KdV and deformed hyperelliptic curves
abstract: We review and summarize recent works on the relation between form factors in integrable quantum field theory and deformation of geometrical data associated to hyper-elliptic curves. This relation, which is based on a deformation of the Riemann bilinear identity, in particular leads to the notion of null vectors in integrable field theory and to a new description of the KdV hierarchy.