A Search for Dark Higgs Bosons

Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb-1 of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the Standard Model-dark sector mixing angle and the dark sector coupling constant.Comment: 7 pages, 5 postscript figures, published version with improved plots for b/w printin

B0 meson decays to rho0 K*0, f0 K*0, and rho-K*+, including higher K* resonances

We present branching fraction measurements for the decays B0 -> rho0 K*0, B0 -> f0 K*0, and B0 -> rho- K*+, where K* is an S-wave (K pi)_0* or a K*(892) meson; we also measure B0 -> f0 K_2*(1430)^0. For the K*(892) channels, we report measurements of longitudinal polarization fractions (for rho final states) and direct CP-violation asymmetries. These results are obtained from a sample of (471.0 +/- 2.8) x 10^6 BBbar pairs collected with the BaBar detector at the PEP-II asymmetric-energy e+ e- collider at the SLAC National Accelerator Laboratory. We observe rho0 K*(892)^0, rho0 (K pi)_0^{*0}, f0 K*(892)^0, and rho- K*(892)+ with greater than 5 sigma significance, including systematics. We report first evidence for f0 (K pi)_0^{*0} and f0 K_2*(1430)^0, and place an upper limit on rho- (K pi)_0^{*+}. Our results in the K*(892) channels are consistent with no direct CP-violation.Comment: 17 pages, 6 postscript figures, submitted to Phys. Rev.

B-meson decays to eta ' rho, eta ' f(0), and eta ' K*

We present measurements of B-meson decays to the final states eta'rho, eta'f(0), and eta'K*, where K* stands for a vector, scalar, or tensor strange meson. We observe a significant signal or evidence for eta'rho(+) and all the eta'K* channels. We also measure, where applicable, the charge asymmetries, finding results consistent with no direct CP violation in all cases. The measurements are performed on a data sample consisting of 467 X 10(6) B (B) over bar pairs, collected with the BABAR detector at the PEP-II e(+)e(-) collider at the SLAC National Accelerator Laboratory. Our results favor the theoretical predictions from perturbative QCD and QCD factorization and we observe an enhancement of the tensor K-2*(1430) with respect to the vector K*(892) component

Amplitude analysis of B^{0}→K^{+}π^{-}π^{0} and evidence of direct CP violation in B→K*π decays

We analyze the decay B(0) -> K(+) pi(-) pi(0) with a sample of 4.54 x 10(8) B (B) over bar events collected by the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC, and extract the complex amplitudes of seven interfering resonances over the Dalitz plot. These results are combined with amplitudes measured in B(0) -> K(S)(0)pi(+)pi(-) decays to construct isospin amplitudes from B(0) -> K* pi and B(0) -> rho K decays. We measure the phase of the isospin amplitude Phi(3/2), useful in constraining the Cabibbo-Kobayashi-Maskawa unitarity triangle angle gamma and evaluate a CP rate asymmetry sum rule sensitive to the presence of new physics operators. We measure direct CP violation in B(0) -> K*(+) pi(-) decays at the level of 3 sigma when measurements from both B(0) -> K(+) pi(-) pi(0) and B(0) -> K(S)(0) pi(+) pi(-) decays are combined

Search for CP violation in the decay τ^{-}→π^{-}K_{s}^{0}(≥Oπ^{0})ν_{τ}

We report a search for CP violation in the decay τ-→π-KS0(≥0π0)ντ using a data set of 437×106 τ-lepton pairs, corresponding to an integrated luminosity of 476  fb-1, collected with the BABAR detector at the PEP-II asymmetric-energy e+e- storage rings. The CP-violating decay-rate asymmetry is determined to be (-0.36±0.23±0.11)% approximately 2.8 standard deviations from the standard model prediction of (0.36±0.01)%

B0 meson decays to ρ0K∗0, f0K∗0, and ρ−K∗+, including higher K∗ resonances

We present branching fraction measurements for the decays B0→ρ0K*0, B0→f0K*0, and B0→ρ-K*+, where K* is an S-wave (Kπ)0* or a K*(892) meson; we also measure B0→f0K2*(1430)0. For the K*(892) channels, we report measurements of longitudinal polarization fractions (for ρ final states) and direct CP violation asymmetries. These results are obtained from a sample of (471.0±2.8)×106 BB̅ pairs collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at the SLAC National Accelerator Laboratory. We observe ρ0K*(892)0, ρ0(Kπ)0*0, f0K*(892)0, and ρ-K*(892)+ with greater than 5σ significance, including systematics. We report first evidence for f0(Kπ)0*0 and f0K2*(1430)0, and place an upper limit on ρ-(Kπ)0*+. Our results in the K*(892) channels are consistent with no direct CP violation

Improved limits on B-0 decays to invisible ( plus gamma) final states

We establish improved upper limits on branching fractions for B-0 decays to final states where the decay products are purely invisible (i.e., no observable final state particles) and for final states where the only visible product is a photon. Within the Standard Model, these decays have branching fractions that are below the current experimental sensitivity, but various models of physics beyond the Standard Model predict significant contributions for these channels. Using 471 x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance by the BABAR experiment at the PEP-II e(+)e(-) storage ring at the SLAC National Accelerator Laboratory, we establish upper limits at the 90% confidence level of 2.4 x 10(-5) for the branching fraction of B-0 -> invisible and 1.7 x 10(-5) for the branching fraction of B-0 -> invisible + gamma