Identification of CIITA Regulated Genetic Module Dedicated for Antigen Presentation

The class II trans-activator CIITA is a transcriptional co-activator required for the expression of Major Histocompatibility Complex (MHC) genes. Although the latter function is well established, the global target-gene specificity of CIITA had not been defined. We therefore generated a comprehensive list of its target genes by performing genome-wide scans employing four different approaches designed to identify promoters that are occupied by CIITA in two key antigen presenting cells, B cells and dendritic cells. Surprisingly, in addition to MHC genes, only nine new targets were identified and validated by extensive functional and expression analysis. Seven of these genes are known or likely to function in processes contributing to MHC-mediated antigen presentation. The remaining two are of unknown function. CIITA is thus uniquely dedicated for genes implicated in antigen presentation. The finding that CIITA regulates such a highly focused gene expression module sets it apart from all other transcription factors, for which large-scale binding-site mapping has indicated that they exert pleiotropic functions and regulate large numbers of genes

Measurement of the polar-angle distribution of leptons from W boson decay as a function of the W transverse momentum in proton-antiproton collisions at sqrt{s}=1.8 TeV

We present a measurement of the coefficient alpha_2 of the leptonic polar-angle distribution from W boson decays, as a function of the W transverse momentum. The measurement uses an 80+/-4 pb^{-1} sample of proton-antiproton collisions at sqrt{s}=1.8 TeV collected by the CDF detector and includes data from both the W->e+nu and W->mu+nu decay channels. We fit the W boson transverse mass distribution to a set of templates from a Monte Carlo event generator and detector simulation in several ranges of the W transverse momentum. The measurement agrees with the Standard Model expectation, whereby the ratio of longitudinally to transversely polarized W bosons, in the Collins-Soper W rest frame, increases with the W transverse momentum at a rate of approximately 15% per 10 GeV/c.Comment: 47 pages, 16 figures, submitted to Physical Review

Observation of the Decay B=> J/psi eta K and Search for X(3872)=> J/psi eta

We report the observation of the $B$ meson decay $B^\pm\to J/\psi \eta K^\pm$ and evidence for the decay $B^0\to J/\psi \eta K^0_S$, using {90} million $BBbar$ events collected at the \ensuremath{\Upsilon{(4S)}}\xspace resonance with the $BaBar$ detector at the PEP-II $e^+ e^-$ asymmetric-energy storage ring. We obtain branching fractions of $\cal{B}$$(B^\pm\to J/\psi \eta K^{\pm}$)=$(10.8\pm 2.3(\rm{stat.})\pm 2.4(\rm{syst.}))\times 10^{-5}$ and $\cal{B}$$(B^0\to J/\psi\eta K_{\rm{S}}^{0}$)=$(8.4\pm 2.6(\rm{stat.})\pm 2.7(\rm{syst.}))\times 10^{-5}$. We search for the new narrow mass state, the X(3872), recently reported by the Belle Collaboration, in the decay B^\pm\to X(3872)K^\pm, X(3872)\to \jpsi \eta and determine an upper limit of $\cal{B}$(B^\pm \to X(3872) K^\pm \to \jpsi \eta K^\pm) $<7.7\times 10^{-6}$ at 90% C.L.Comment: 7 pages and two figures, submitted to Phys. Rev. Lett

Measurements of the branching fraction and CP-violation asymmetries in B-0 -> f(0)(980)K-S(0)

We present measurements of the branching fraction and CP-violating asymmetries in the decay B-0-->f(0)(980)K-S(0). The results are obtained from a data sample of 123x10(6) Y(4S)-->B (B) over bar decays. From a time-dependent maximum likelihood fit, we measure the branching fraction B(B-0-->f(0)(980)(-->pi(+)pi(-))K-0)=(6.0+/-0.9+/-0.6+/-1.2)x10(-6), the mixing-induced CP violation parameter S=-1.62(-0.51)(+0.56)+/-0.09+/-0.04, and the direct CP violation parameter C=0.27+/-0.36+/-0.10+/-0.07, where the first errors are statistical, the second systematic, and the third due to model uncertainties. We measure the f(0)(980) mass and width to be m(f0)(980)=(980.6+/-4.1+/-0.5+/-4.0) MeV/c(2) and Gamma(f0)(980)=(43(-9)(+12)+/-3+/-9) MeV/c(2), respectively

Search for lepton-flavor violation in the decay tau(-)-> l(-)l(+)l-

A search for the lepton-flavor-violating decay of the tau into three charged leptons has been performed using 91.5 fb(-1) of data collected at an e(+)e(-)center-of-mass energy around 10.58 GeV with the BABAR detector at the SLAC storage ring PEP-II. In all six decay modes considered, the numbers of events found in data are compatible with the background expectations. Upper limits on the branching fractions are set in the range (1-3)x10(-7) at 90% confidence level

Measurements of branching fractions and CP-violating asymmetries in B meson decays to charmless two-body states containing a K-0

We present measurements of branching fractions and CP-violating asymmetries in decays of B mesons to two-body final states containing a K-0. The results are based on a data sample of approximately 88x10(6) Y(4S)-->B (B) over bar decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We measure B(B+-->K(0)pi(+))=(22.3+/-1.7+/-1.1)x10(-6), B(B-0-->K(0)pi(0))=(11.4+/-1.7+/-0.8)x10(-6), B(B+-->(K) over bar K-0(+))K-0(K) over bar (0))K(0)pi(+))=-0.05+/-0.08+/-0.01 and A(CP)(B-0-->K(0)pi(0))=0.03+/-0.36+/-0.11

Search for the rare leptonic decay B+->mu(+)nu(mu) (vol 92, art no 221803, 2004)

Corrections to the article published in the same review - same title (vol 92, art no 221803, 2004