5119980
Measurement of semileptonic B decays into orbitally excited charmed mesons.
We present a study of B decays into semileptonic final states containing charged and neutral D1(2420) and D_{2};{*}(2460). The analysis is based on a data sample of 208 fb;{-1} collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. With a simultaneous fit to four different decay chains, the semileptonic branching fractions are extracted from measurements of the mass difference Deltam=m(D;{**})-m(D) distributions. Product branching fractions are determined to be B(B;{+}-->D_{1};{0}l;{+}nu_{l})xB(D_{1};{0}-->D;{*+}pi;{-})=(2.97+/-0.17+/-0.17)x10;{-3}, B(B;{+}-->D_{2};{*0}l;{+}nu_{l})xB(D_{2};{*0}-->D;{(*)+}pi;{-})=(2.29+/-0.23+/-0.21)x10;{-3}, B(B;{0}-->D_{1};{-}l;{+}nu_{l})xB(D_{1};{-}-->D;{*0}pi;{-})=(2.78+/-0.24+/-0.25)x10;{-3} and B(B;{0}-->D_{2};{*-}l;{+}nu_{l})xB(D_{2};{*-}-->D;{(*)0}pi;{-})=(1.77+/-0.26+/-0.11)x10;{-3}. In addition we measure the branching ratio Gamma(D_{2};{*}-->Dpi;{-})/Gamma(D_{2};{*}-->D;{(*)}pi;{-})=0.62+/-0.03+/-0.02.
125343210
Measurement of the CKM matrix element $|V_{ub}|$ with $B \to \rho e \nu$ decays
126404399
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
120104270
Operation of the Cherenkov detector DIRC of BABAR at high luminosity
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.
21907946
Search for T, CP, and CPT violation in B0-B0 mixing with inclusive dilepton events.
We report the results of a search for T, CP, CPT, and violation in B0-B0 mixing using an inclusive dilepton sample collected by the BABAR experiment at the PEP-II factory. Using a sample of 232 x 10(6) BB pairs, we measure the T and CP violation parameter |q/p| - 1 = (-0.8 +/- 2.7(stat) +/- 1.9(syst) x 10(-3), and the CPT and CP parameters Imz = (13.9 +/- 7.3(stat) +/- 3.2(syst)) x 10(-3) and Delta Gamma x Rez = (7.1 +/- 3.9(stat) +/- 2.0(stat)) x 10(-3) ps(-1). The statistical correlation between the measurements of Imz and Delta Gamma x Rez is 76%.
202048438
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
17641456
Spin-Charge Separation and the Spin Quantum Hall Effect
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.
122663046
Quantum Lie algebras and differential calculus on quantum groups
33626790
An insulating grid spacer for large-area MICROMEGAS chambers
Abstract We present a novel design for large-area gaseous detectors based on the MICROMEGAS technology. This technology incorporates an insulating grid, sandwiched between the micro-mesh and the anode-pad plane, which provides a uniform 200 μm amplification gap. The uniformity of the amplification gap thickness has been verified. The gain performances of the detector are presented and compared to the values obtained with detectors using cylindrical micro spacers. The new design presents several technical and financial advantages.
18013997
Yang-Baxter equation in spin chains with long range interactions
We consider the $ su(n) $ spin chains with long range interactions and the spin generalization of the Calogero-Sutherland models. We show that their properties derive from a transfer matrix obeying the Yang-Baxter equation. We obtain the expression of the conserved quantities and we diagonalize them.
14691638
Nonperturbative renormalization in a scalar model within light-front dynamics
Within the covariant formulation of Light-Front Dynamics, in a scalar model with the interaction Hamiltonian $H=-g\psi^{2}(x)\phi(x)$, we calculate nonperturbatively the renormalized state vector of a scalar "nucleon" in a truncated Fock space containing the $N$, $N\pi$ and $N\pi\pi$ sectors. The model gives a simple example of non-perturbative renormalization which is carried out numerically. Though the mass renormalization $\delta m^2$ diverges logarithmically with the cutoff $L$, the Fock components of the "physical" nucleon are stable when $L\to\infty$.