Study of radiative bottomonium transitions using converted photons
We use (111 +/- 1) million Gamma(3S) and (89 +/- 1) million Gamma(2S) events recorded by the BABAR detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions between bottomonium states using photons that have been converted to e(+)e(-) pairs by the detector material. We observe Gamma(3S) -> gamma chi b(0,2)(1P) decay, make precise measurements of the branching fractions for chi b(1,2)(1P, 2P) -> gamma Gamma(1S) and chi b(1,2)(2P) -> gamma Gamma(2S) decays, and search for radiative decay to the eta(b)(1S) and eta(b)(2S) states.

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

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

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: 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: The quantum double in integrable quantum field theory
abstract: Various aspects of recent works of affine quantum group symmetry of integrable 2D quantum field theory are reviewed and further clarified. A geometrical meaning is given to the quantum double, and other properties of quantum groups. The S-matrix is identified with the universal R-matrix. Multiplicative presentations of the yangian double are analyzed.

title: A One Dimensional Ideal Gas of Spinons, or Some Exact Results on the XXX Spin Chain with Long Range Interaction
abstract: We describe a few properties of the XXX spin chain with long range interaction. The plan of these notes is: 
 
1 
 
— The Hamiltonian. 
 
 
 
 
2 
 
— Symmetry of the model. 
 
 
 
 
3 
 
— The irreducible multiplets. 
 
 
 
 
4 
 
— The spectrum. 
 
 
 
 
5 
 
— Wave functions and statistics. 
 
 
 
 
6 
 
— The spinon description. 
 
 
 
 
7 
 
— The thermodynamics.

title: AFFINE SOLITONS: A RELATION BETWEEN TAU FUNCTIONS, DRESSING AND BÄCKLUND TRANSFORMATIONS
abstract: We reconsider the construction of solitons by dressing transformations in the sine-Gordon model. We show that the N-soliton solutions are in the orbit of the vacuum, and we identify the elements in the dressing group which allow us to build the N-soliton solutions from the vacuum solution. The dressed τ functions can be computed in two different ways: either using adjoint actions in the affine Lie algebra , and this gives the relation with the Backlund transformations, or using the level-one representations of the affine Lie algebra , and this directly gives the formulae for the τ functions in terms of vertex operators.

title: On the random vector potential model in two dimensions
abstract: The random vector potential model describes massless fermions coupled to a quenched random gauge field. We study its abelian and non-abelian versions. The abelian version can be completely solved using bosonization. We analyse the non-abelian model using its supersymmetric formulation and show, by a perturbative renormalization group computation, that it is asymptotically free at large distances. We also show that all the quenched chiral current correlation functions can be computed exactly, without using the replica trick or the supersymmetric formulation, but using an exact expression for the effective action for any sample of the random gauge field. These chiral correlation functions are purely algebraic.