Search for rare quark-annihilation decays, B --> Ds(*) Phi

We report on searches for B- --> Ds- Phi and B- --> Ds*- Phi. In the context of the Standard Model, these decays are expected to be highly suppressed since they proceed through annihilation of the b and u-bar quarks in the B- meson. Our results are based on 234 million Upsilon(4S) --> B Bbar decays collected with the BABAR detector at SLAC. We find no evidence for these decays, and we set Bayesian 90% confidence level upper limits on the branching fractions BF(B- --> Ds- Phi) Ds*- Phi)<1.2x10^(-5). These results are consistent with Standard Model expectations.Comment: 8 pages, 3 postscript figues, submitted to Phys. Rev. D (Rapid Communications

A Precision Measurement of the Lambda_c Baryon Mass

The $\Lambda_c^+$ baryon mass is measured using $\Lambda_c^+\to\Lambda K^0_S K^+$ and $\Lambda_c^+\to\Sigma^0 K^0_S K^+$ decays reconstructed in 232 fb$^{-1}$ of data collected with the BaBar detector at the PEP-II asymmetric-energy $e^+e^-$ storage ring. The $\Lambda_c^+$ mass is measured to be $2286.46\pm0.14\mathrm{MeV}/c^2$. The dominant systematic uncertainties arise from the amount of material in the tracking volume and from the magnetic field strength.Comment: 14 pages, 8 postscript figures, submitted to Phys. Rev.

Search for radiative penguin decays B+->rho(+)gamma, B-0 ->rho(0)gamma, and B-0 ->omega gamma

A search for the decays B-->rho(770)gamma and B-0-->omega(782)gamma is performed on a sample of 211x10(6) Y(4S)-->B (B) over bar events collected by the BABAR detector at the SLAC PEP-II asymmetric-energy e(+)e(-) storage ring. No evidence for the decays is seen. We set the following limits on the individual branching fractions: B(B+-->rho(+)gamma)rho(0)gamma)omegagamma)(rho/omega)gamma]<1.2x10(-6), from which we determine a constraint on the ratio of Cabibbo-Kobayashi-Maskawa matrix elements |V-td|/|V-ts|

Search for the decay B+-> K+ v(v)over-bar

We search for the rare flavor-changing neutral-current decay B+ -> K+ v (v) over tilde in a data sample of 82 fb(-1) collected with the BABAR detector at the PEP-II B-factory. Signal events are selected by examining the properties of the system recoiling against either a reconstructed hadronic or semileptonic charged-B decay. Using these two independent samples we obtain a combined limit of B(B+ -> K+ v (v) over bar) pi(+) v (v) over bar) < 1.0 x 10(-4) using only the hadronic B reconstruction method

Search for strange-pentaquark production in e(+)e(-) annihilation at root s=10.58 GeV

We search for strange-pentaquark states that have been previously reported by other experiments-the Theta(1540)(+), Xi(5)(1860)(--), and Xi(5)(1860)(0)-in 123 fb(-1) of data recorded with the BABAR detector at the PEP-II e(+)e(-) storage ring. We find no evidence for these states and set 95% confidence level upper limits on the number of Theta(1540)(+) and Xi(5)(1860)(--) pentaquarks produced per e(+)e(-) annihilation into q (q) over bar and per Upsilon(4S) decay. For q (q) over bar events the Theta(1540)(+) [Xi(5)(1860)(--)] limit is about 8 [4] times lower than the rates measured for ordinary baryons of similar mass

Measurement of branching fractions and mass spectra of B -> K pi pi gamma (vol 98, art no 211804, 2007)

Contains fulltext : 71970.pdf (publisher's version ) (Open Access)2 p

Measurement of branching fractions and mass spectra of B -> K pi pi gamma

We present a measurement of the partial branching fractions and mass spectra of the exclusive radiative penguin processes B -> K pi pi gamma in the range m(K pi pi)pi(+)pi(-). Using 232x10(6) e(+)e(-)-> B (B) over bar events recorded by the BABAR experiment at the SLAC PEP-II asymmetric-energy storage ring, we measure the branching fractions B(B+-> K+pi(-)pi(+)gamma)=[2.95 +/- 0.13(stat)+/- 0.20(syst)]x10(-5), B(B-0 -> K+pi(-)pi(0)gamma)=[4.07 +/- 0.22(stat)+/- 0.31(syst)]x10(-5), B(B-0 -> K-0 pi(+)pi(-)gamma)=[1.85 +/- 0.21(stat)+/- 0.12(syst)]x10(-5), and B(B+-> K-0 pi(+)pi(0)gamma)=[4.56 +/- 0.42(stat)+/- 0.31(syst)]x10(-5)

Search for the rare decay B-0 ->tau(+)tau(-) at BABAR

We present the results of a search for the decay B-0 ->tau(+)tau(-) in a data sample of (232 +/- 3)x10(6) Upsilon(4S)-> BB decays using the BABAR detector. Certain extensions of the standard model predict measurable levels of this otherwise rare decay. We reconstruct fully one neutral B meson and seek evidence for the signal decay in the rest of the event. We find no evidence for signal events and obtain B(B-0 ->tau(+)tau(-))< 4.1x10(-3) at the 90% confidence level