Showing papers by "Michael Levi published in 2004"
TL;DR: In this article, 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.
Abstract: 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.
69 citations
TL;DR: In this article, the BaBar detector was used to detect the B-meson decays to K+ pi-pi- pi+ with a data sample of 61.6 million BBbar pairs.
Abstract: We present results of searches for B-meson decays to K+ pi- pi+ with the BaBar detector. With a data sample of 61.6 million BBbar pairs, we measure the branching fractions and 90% confidence-level upper limits averaged over charge-conjugate states (the first error is statistical and the second is systematic): B+ --> K*0 pi+ = (15.5 +/- 1.8 +1.5 -4.0) x 10^-6, B+ --> f0 K+, f_0 --> pi+ pi- = (9.2 +/- 1.2 +2.1 -2.6) x 10^-6, B+ --> D0bar pi+, D0bar --> K+ pi- = (184.6 +/- 3.2 +/- 9.7) x 10^-6. B+ --> rho K+ K+ pi- pi+ non-resonant < 17 x 10^-6.
38 citations
TL;DR: A study of B--->D(0)(CP)K- decays, where D(0) is reconstructed in CP-even channels, based on a sample of 88.8 x 10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II e(+)e(-) storage ring.
Abstract: We present a study of B--->D(0)(CP)K- decays, where D(0)(CP) is reconstructed in CP-even channels, based on a sample of 88.8 x 10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II e(+)e(-) storage ring. We measure the ratio of Cabibbo-suppressed to Cabibbo-favored branching fractions B(B--->D(0)(CP)K-)/B(B--->D(0)(CP)pi(-))=[8.8+/-1.6(stat)+/-0.5(syst)]x10(-2) and the CP asymmetry A(CP)=0.07+/-0.17(stat)+/-0.06(syst). We also measure B(B--->D0K-)/B(B--->D0pi(-))=[8.31+/-0.35(stat)+/-0.20(syst)]x10(-2) using a sample of 61.0 x 10(6) BB pairs.
18 citations
TL;DR: In this article, a search for the rare leptonic decay B+→μ+νμ with data collected at the Υ(4S) resonance by the BABAR experiment at the PEP-II storage ring was performed.
Abstract: We have performed a search for the rare leptonic decay B+→μ+νμ with data collected at the Υ(4S) resonance by the BABAR experiment at the PEP-II storage ring In a sample of 884×106 BB pairs, we find no significant evidence for a signal and set an upper limit on the branching fraction B(B+→μ+νμ)<66×10-6 at the 90% confidence level
16 citations
TL;DR: In this paper, the authors measured the branching fractions and charge asymmetries for seven B-meson decays with an eta, eta', or omega meson in the final state, and the data sample corresponds to 89x10(6) BB pairs produced from e(+)e(-) annihilation at the Upsilon(4S) resonance.
Abstract: We present measurements of branching fractions and charge asymmetries for seven B-meson decays with an eta, eta', or omega meson in the final state. The data sample corresponds to 89x10(6) BB pairs produced from e(+)e(-) annihilation at the Upsilon(4S) resonance. We measure the following branching fractions in units of 10(-6): B(B+-->eta pi(+))=5.3+/-1.0+/-0.3, B(B+-->eta K+)=3.4+/-0.8+/-0.2, B(B0-->eta K0)=2.9+/-1.0+/-0.2 ( eta(')pi(+))=2.7+/-1.2+/-0.3 ( omega pi(+))=5.5+/-0.9+/-0.5, B(B+-->omega K+)=4.8+/-0.8+/-0.4, and B(B0-->omega K0)=5.9(+1.6)(-1.3)+/-0.5. The charge asymmetries are A(ch)(B+-->eta pi(+))=-0.44+/-0.18+/-0.01, A(ch)(B+-->eta K+)=-0.52+/-0.24+/-0.01, A(ch)(B+-->omega pi(+))=0.03+/-0.16+/-0.01, and A(ch)(B+-->omega K+)=-0.09+/-0.17+/-0.01.
14 citations
TL;DR: A study of the decay B--->D(*0)K(*-) based on a sample of 86 x 10(6) Upsilon(4S)-->BBmacr; decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC.
Abstract: We present a study of the decay B- --> D*K-0*(-) based on a sample of 86 X 10(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 the branching fraction 23(B- --> D*K-0*(-)) = (8.3 +/- 1.1(stat) +/- 1.0(syst)) X 10(-4), and the fraction of longitudinal polarization in this decay to be Gamma(L)/Gamma = 0.86 +/- 0.06(stat) --> +/- 0.03(syst).
12 citations
University of California, Berkeley1, University of Michigan2, Lawrence Berkeley National Laboratory3, Stockholm University4, Centre national de la recherche scientifique5, Yale University6, University of Pennsylvania7, Space Telescope Science Institute8, Indiana University9, American Astronomical Society10, California Institute of Technology11
TL;DR: The SuperNova/Acceleration Probe (SNAP) space mission as discussed by the authors uses the annular-field three-mirror anastigmat (TMA) telescope configuration, whose classical aberrations (including chromatic) are zero.
Abstract: We present the baseline telescope design for the telescope for the SuperNova/Acceleration Probe (SNAP) space mission. SNAP’s purpose is to determine expansion history of the Universe by measuring the redshifts, magnitudes, and spectral classifications of thousands of supernovae with unprecedented accuracy. Discovering and measuring these supernovae demand both a wide optical field and a high sensitivity throughout the visible and near IR wavebands. We have adopted the annular-field three-mirror anastigmat (TMA) telescope configuration, whose classical aberrations (including chromatic) are zero. We show a preliminary optmechanical design that includes important features for stray light control and on-orbit adjustment and alignment of the optics. We briefly discuss stray light and tolerance issues, and present a preliminary wavefront error budget for the SNAP Telescope. We conclude by describing some of the design tasks being carried out during the current SNAP research and development phase.
10 citations
TL;DR: A measurement of time-dependent CP-violating asymmetries in decays of neutral B mesons to the final states D(*-/+)pi(+/-), using approximately 82x10(6) BBmacr; events recorded by the BABAR experiment at the PEP-II e(+)e(-) storage ring are presented.
Abstract: We present a preliminary measurement of the time-dependent CP-violating asymmetry in decays of neutral B mesons to the final states D*-+ pi+- using approximately 178 million BB events recorded by the BaBar experiment at the PEP-II e+e- storage ring. Events containing these decays are selected with a partial reconstruction technique, in which only the high-momentum pi+- from the B decay and the low-momentum pi-+ from the D*-+ decay are used. % We measure the amplitude of the asymmetry to be $-0.041 \pm 0.016 (stat.) \pm 0.010 (syst.)$ and determine bounds on $|\sin(2 \beta + \gamma)|$.
10 citations
TL;DR: Measurements of branching fractions and CP-violating asymmetries in decays of B mesons to two-body final states containing a K0.
Abstract: We present measurements of branching fractions and \CP-violating asymmetries in decays of $B$ mesons to two-body final states containing a \Kz. The results are based on a data sample of approximately 88 million \upsbb decays collected with the \babar detector at the \pep2 asymmetric-energy $B$ Factory at SLAC. We measure $\BR(\Bp\to\Kz\pip) = (22.3 \pm 1.7 \pm 1.1)\times 10^{-6}$, $\BR(\Bz\to\Kz\piz) = (11.4\pm 1.7\pm 0.8)\times 10^{-6}$, $\BR(\Bp\to\Kzb\Kp) < 2.5\times 10^{-6}$, and $\BR(\Bz\to\KzKzb) < 1.8\times 10^{-6}$, where the first uncertainty is statistical and the second is systematic, and the upper limits are at the 90% confidence level. In addition, the following \CP-violating asymmetries have been measured: ${\cal A}_{CP}(\Bp\to\Kz\pip) = -0.05 \pm 0.08 \pm 0.01$ and ${\cal A}_{CP}(\Bz\to\Kz\piz) = 0.03 \pm 0.36\pm 0.11$.
9 citations
TL;DR: In this paper, the authors present new characterization results for a large format, 15 um pixel pitch, 2kx4k format, p-channel CCD fabricated on high resistivity silicon at Lawrence Berkeley National Laboratory.
Abstract: We present new characterization results for a large format, 15 um pixel pitch, 2kx4k format, p-channel CCD fabricated on high resistivity silicon at Lawrence Berkeley National Laboratory. The fully-depleted device is 300 um thick and backside illuminated utilizing 4-side buttable packaging. We report on measurements of standard operating characteristics including charge transfer efficiency, readout noise, cosmetics performance, dark current, and well depth. We have also made preliminary measurements of the device's X-Ray energy resolution and tests of device linearity.
8 citations
TL;DR: In this article, the authors developed a 4-side buttable CCD package for 2kx2k and 2k-4k format devices with minimal mechanical stress on the CCD, excellent thermal properties, reliable electrical connectivity, and shim-free mounting.
Abstract: We have developed a precision, 4-side buttable CCD package for 2kx2k and 2kx4k format devices with minimal mechanical stress on the CCD, excellent thermal properties, reliable electrical connectivity, and shim-free mounting. We report on the package design, assembly and quality assurance procedures, measurements of packaged device flatness and flatness excursions when cooled from room temperature to 140 K, package performance and plans for future development.
TL;DR: In this paper, a search for the exclusive radiative decays B {yields} {rho}(770){gamma} and B{sup 0, yields] {omega}(782]-gamma is performed on a sample of about 84 million B{bar B} events collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring.
Abstract: A search for the exclusive radiative decays B {yields} {rho}(770){gamma} and B{sup 0} {yields} {omega}(782){gamma} is performed on a sample of about 84 million B{bar B} events collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring. No significant signal is seen in any of the channels. We set upper limits on the branching fractions {Beta} of {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) < 1.2 x 10{sup -6}, {Beta}(B{sup +} {yields} {rho}{sup +}{gamma}) < 2.1 x 10{sup -6}, and {Beta}(B{sup 0} {yields} {omega}{gamma}) < 1.0 x 10{sup -6} at 90% confidence level (C.L.). Using the assumption that {Lambda}(B {yields} {rho}{gamma}) = {Lambda}(B{sup +} {yields} {rho}{sup +}{gamma}) = 2 x {Lambda}(B{sup 0} {yields} {rho}{sup 0}{gamma}), they find the combined limit {Beta}(B {yields} {rho}{gamma}) < 1.9 x 10{sup -6}, corresponding to {Beta}(B {yields} {rho}{gamma})/{Beta}(B {yields} {rho}{gamma})/{Beta}(B {yields} K*{gamma}) < 0.047 at 90% C.L.
TL;DR: In this article, the average multiplicity of {phi} mesons in B{sup 0, {bar B}{sup 0} and B{Sup {+-}} meson decays was measured using 17.6 fb{sup -1} of data taken at the BABAR detector at the PEP-II e{sup +}e{sup-} storage ring at the Stanford Linear Accelerator Center.
Abstract: The authors present a measurement of the average multiplicity of {phi} mesons in B{sup 0}, {bar B}{sup 0} and B{sup {+-}} meson decays. Using 17.6 fb{sup -1} of data taken at the {Upsilon}(4S) resonance by the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring at the Stanford Linear Accelerator Center, they reconstruct {phi} mesons in the K{sup +}K{sup -} decay mode and measure {Beta}(B {yields} {phi}X) = (3.41 {+-} 0.06 {+-} 0.12)%. This is significantly more precise than any previous measurement.