HARPO: a TPC as a gamma-ray telescope and polarimeter
A gas Time Projection Chamber can be used for gamma-ray astronomy with excellent angular-precision and sensitivity to faint sources, and for polarimetry, through the measurement of photon conversion to e+e− pairs. We present the expected performance in simulations and the recent development of a demonstrator for tests in a polarized photon beam.

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: 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: Conformal Field Theories of Stochastic Loewner Evolutions
abstract: Stochastic Loewner evolutions (SLEκ) are random growth processes of sets, called hulls, embedded in the two dimensional upper half plane. We elaborate and develop a relation between SLEκ evolutions and conformal field theories (CFT) which is based on a group theoretical formulation of SLEκ processes and on the identification of the proper hull boundary states. This allows us to define an infinite set of SLEκ zero modes, or martingales, whose existence is a consequence of the existence of a null vector in the appropriate Virasoro modules. This identification leads, for instance, to linear systems for generalized crossing probabilities whose coefficients are multipoint CFT correlation functions. It provides a direct link between conformal correlation functions and probabilities of stopping time events in SLEκ evolutions. We point out a relation between SLEκ processes and two dimensional gravity and conjecture a reconstruction procedure of conformal field theories from SLEκ data.

title: Multiple Schramm–Loewner Evolutions and Statistical Mechanics Martingales
abstract: A statistical mechanics argument relating partition functions to martingales is used to get a condition under which random geometric processes can describe interfaces in 2d statistical mechanics at criticality. Requiring multiple SLEs to satisfy this condition leads to some natural processes, which we study in this note. We give examples of such multiple SLEs and discuss how a choice of conformal block is related to geometric configuration of the interfaces and what is the physical meaning of mixed conformal blocks. We illustrate the general ideas on concrete computations, with applications to percolation and the Ising model

title: Level one representations of the simple affine Kac-Moody algebras in their homogeneous gradations
abstract: Using the central charge of the Virasoro algebra as a clue, we recall the known constructions of theA, D, E algebras and discuss new Bosonic constructions of the non simply laced affine Kac-Moody algebras: the twistedA, D, E and theB, C, F, andG algebras. These involve interacting Fermions and a generalization of the Frenkel-Kac sign operators which do not form a 2-cocycle when the horizontal algebra has more than one short simple root.

title: Conformal field theories in random domains and stochastic Loewner evolutions
abstract: We review the recently developed relation between the traditional algebraic approach to conformal field theories and the more recent probabilistic approach based on stochastic Loewner evolutions. It is based on implementing random conformal maps in conformal field theories.

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.