Improved Measurements of Branching Fractions and CP Asymmetries in B-> eta h Decays

We report improved measurements of B decays with an eta meson in the final state using 357 fb^-1 of data collected by the Belle detector at the KEKB e^+ e^- collider. We observe the decays B^+- ->eta pi^+- and B^+- -> eta K^+-; the measured branching fractions are Br(B^+- -> eta pi^+-) = (3.9 +- 0.5(stat.)+-0.2(sys.))*10^-6 and Br(B^+- -> eta K^+-) = (2.2+-0.4(stat.)+-0.1(sys.))*10^-6, respectively. Their corresponding CP-violating asymmetries are measured to be -0.10+-0.11(stat.)+-0.02(sys.) for eta pi^+- and -0.55+-0.19(stat.)+0.04-0.03(sys.) for eta K^+-. No significant signal is found for B^0-> eta K^0 decays; the upper limit on the branching fraction at the 90% confidence level is Br(B^0->eta K^0) < 1.9*10^-6.Comment: 11 pages, 3 figures, BELLE-CONF-0525, EPS05 49

High PT Physics with the STAR Experiment at RHIC

The STAR experiment at RHIC is a TPC-based, general purpose detector designed to obtain charged particle spectra, with an emphasis on hadrons over a large phase space. An electromagnetic calorimeter provides measurement of electrons, photons, pi-zeros and jets. Data-taking with Au+Au collisions at sqrt(s)= 200 GeV/c**2 begins in Fall 1999. The STAR experiment's investigation of techniques and signals using hard probes to study the high energy-density matter at RHIC and to search for quark-gluon plasma formation will be described.Comment: 5 pages, 4 figures, latex2e using ws-p8-50x6-00, for publication in Proceedings of the Relativistic Heavy Ion Mini-Symposium at the APS Centennial, Atlanta, 199

Energy Spectra and Elemental Composition of Nuclei above 100 TeV from a Series of JACEE Balloon Flights

The Japanese-American Cooperative Emulsion Experiment (JACEE) has recently carried out a series of Antarctic circumpolar balloon flights (JACEE-10 ~ JACEE-13) for the study of high energy elemental composition and energy spectra of cosmic rays. The total exposure factor of these experiments is 663 m**2-hr, which is about twice the cumulative exposure from JACEE-1 through JACEE-8. Preliminary results from the Antarctic flights have been included in the cumulative JACEE spectrum.Comment: Paper presented by T. Tominaga at the 24th Int'l Cosmic Ray Conference. Two postscript files, compressed and uuencoded by uufiles, one containing the text (jcicrc95.uu, 18 kB), and the other the figures (jcicrc95figs.uu, 980 kB), self-unpacking. Submitted by R. Jeffrey Wilkes (Department of Physics, University of Washington, Seattle, WA 98195

Measurement of B -> D_s K pi branching ratios

We report a measurement of the exclusive $B^+$ meson decay to the final state $D_s^- K^+\pi^+$ using $520 \times 10^{6} B\bar{B}$ pairs collected near the $\Upsilon(4S)$ resonance, with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. Using the $D_S^- \to \phi \pi^-$ decay mode to reconstruct $D_s^-$ mesons, we obtain the branching fraction ${\cal B}(B^+\to D_s^-K^+\pi^+)= (1.77^{+0.12}_{-0.12} {\mathrm (stat)} \pm 0.16 {\mathrm (syst)} \pm 0.23 {\cal(B)})\times 10^{-4}$. We also present preliminary results of a study of the two-body $D_sK$, $D_s\pi$ and $K\pi$ subsystems observed in this final state.Comment: 22 pages, 12 figures, submitted to the 2007 Lepton-Photon Symposiu

Observation of Color-Suppressed B‾0→D(∗)0X0\overline{B}^0 \to D^{(*)0}X^0 Decays

We report the first observation of color-suppressed $\overline{B}^0\to D^0 \pi^0$ and $D^{(*)0} \omega$ decays and evidence of $\overline{B}^0 \to D^{*0} \pi^0$ and $D^{(*)0} \eta$. The branching fractions are found to be ${\cal B} (\overline{B}^0\to D^0 \pi^0) = (2.9 ^{+0.4}_{-0.3} \pm 0.6) \times 10^{-4}$, ${\cal B} (\overline{B}^0 \to D^0 \omega) = (1.7 ^{+0.5 +0.3}_{-0.4 -0.4}) \times 10^{-4}$, and ${\cal B} (\overline{B}^0 \to D^{*0} \omega) = (3.4 ^{+1.3}_{-1.1}\pm 0.8) \times 10^{-4}$. The analysis is based on a data sample of 21.3 fb$^{-1}$ collected at the $\Upsilon(4S)$ resonance by the Belle detector at the KEKB $e^{+} e^{-}$ collider.Comment: paper submitted to the 2001 Lepton Photon Conferenc

Precise measurement of hadronic τ\tau-decays in modes with η\eta mesons

We have measured branching fractions of hadronic $\tau$ decays involving an $\eta$ meson using 485 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We obtain the following branching fractions: ${\cal B}(\tau^-\to K^- \eta \nu_{\tau})=(1.62\pm 0.05 \pm 0.09)\times 10^{-4}$, ${\cal B}(\tau^-\to K^- \pi^0 \eta \nu_{\tau}) =(4.7\pm 1.1 \pm 0.4)\times 10^{-5}$, ${\cal B}(\tau^-\to \pi^- \pi^0 \eta \nu_{\tau})=(1.39 \pm 0.03 \pm 0.07) \times 10^{-3}$, and ${\cal B}(\tau^-\to K^{*-} \eta \nu_{\tau})=(1.13\pm 0.19 \pm 0.07)\times 10^{-4}$ improving the accuracy compared to the best previous measurements by factors of six, eight, four and four, respectively.Comment: BELLE-CONF-0714; contributed to EPS 2007 and Lepton Photon 200

Measurement of AcA_c with charmed mesons at SLD

We present a direct measurement of the parity-violation parameter A_c. The measurement is based on 550k Z^0 decays collected by the SLD detector. The mean electron-beam polarization is |P_e| = 73 %. The tagging of c-quark events was performed using two methods: The exclusive reconstruction of D^*+, D^+, and D^0 mesons, and the inclusive P_T spectrum of soft-pions (pi_s) in the decay of D^*+ -> D^0 pi_s^+. The results of these two methods are combined to give A_c = 0.688 +- 0.035(stat.) +- 0.025(sys.) (preliminary).Comment: 12 pages 4 figures Latex. Contributed to EPS99 and to Lepton-Photon9

A Preliminary Direct Measurement of the s-Quark Coupling

We present an updated direct measurement of the parity-violating coupling of the Z boson to strange quarks, A_s, derived from the full SLD data sample of approximately 550,000 hadronic decays of Z bosons produced with a polarized electron beam and recorded by the SLD experiment at SLAC between 1993 and 1998. Events with primary strange quarks are tagged by the presence in each event hemisphere of a high-momentum charged K meson, neutral K meson or Lambda hyperon identified using the Cherenkov Ring Imaging Detector and/or a mass tag. The CCD vertex detector is used to suppress the background from heavy flavor events. The strangeness of the tagged particle is used to sign the event thrust axis in the direction of the initial strange quark. The coupling A_s is obtained directly from a measurement of the left-right-forward-backward production asymmetry in polar angle of the tagged strange quark. The background from primary up and down events is measured from the data, as is the analyzing power of the method for primary strange events. We measure: A_s = 0.85 +- 0.06(stat.) +- 0.07(syst.) (preliminary).Comment: 23 pages, 2 figure

Time-Dependent CP Asymmetries in b --> s qbar q Transitions and sin2phi1 in B0 --> J/psi K0 Decays with 386 Million BBbar Pairs

We present measurements of time-dependent CP asymmetries in B0 --> phi(1020) K0, eta' K0, Ks Ks Ks, Ks pi0, f0(980) Ks, omega Ks and K+ K- Ks decays based on a sample of 386 x 10^6 BBbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. These decays are dominated by the b --> s gluonic penguin transition and are sensitive to new CP-violating phases from physics beyond the standard model. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters sin2phi1^eff and {\cal A} for each of the decay modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays. We also perform an improved measurement of CP asymmetries in B0 --> J/psi K0 decays using the same data sample. The same analysis procedure mentioned above yields sin2phi1 = +0.652 +/- 0.039(stat) +/- 0.020(syst), which serves as a reference point for the standard model, and {\cal A} = +0.010 +/- 0.026(stat) +/- 0.036(syst).Comment: 36 pages, 17 figures, contributed to the XXII International Symposium on Lepton-Photon Interactions at High Energy (Lepton-Photon 2005), June 30 - July 5, 2005, Uppsala, Swede

Measurement of the B+ and B0 Lifetimes using Topological Vertexing at SLD

The lifetimes of B+ and B0 mesons have been measured using the entire sample of 550,000 hadronic Z0 decays collected by the SLD experiment at the SLC between 1993 and 1998. In this paper, we describe the inclusive analysis of the 350,000 hadronic Z0 decays collected in 1997-98 with the upgraded SLD vertex detector. In this data period, a high statistics sample of 30903 (20731) charged (neutral) vertices with good charge purity is obtained. The charge purity is enhanced by using the vertex mass, the SLC electron beam polarization (73% for 1997-8) and an opposite hemisphere jet charge technique. Combining the results of this data sample with the results from the earlier data yield the following preliminary values: $\tau_{B^+}=1.623\pm0.020($stat$)\pm0.034$(syst) ps, $\tau_{B^0}=1.589\pm0.021($stat$)\pm0.043$(syst) ps, $\tau_{B^+}/\tau_{B^0} = 1.037\pm^{0.025}_{0.024}($stat$) \pm0.024$(syst).Comment: 19 pages, 4 figures, submitted to EPS99 and Lepton-Photon 9