23650576
Limits on gravitational-wave emission from selected pulsars using LIGO data.
We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10(-24). These strain limits translate into limits on the equatorial ellipticities of the pulsars, which are smaller than 10(-5) for the four closest pulsars.
16089528
Observation of radiative leptonic decay of the tau lepton
Using 4.68 fb(-1) of e(+)e(-) annihilation data collected with the CLEO II detector at the Cornell Electron Storage Ring, we have studied tau radiative decays tau(-)-->nu(tau)&mgr;(-)nu;(&mgr;)gamma and tau(-)-->nu(tau)e(-)nu;(e)gamma. For a 10 MeV minimum photon energy in the tau rest frame, the branching fraction for radiative tau decay to a muon or electron is measured to be (3.61+/-0.16+/-0. 35)x10(-3) or (1.75+/-0.06+/-0.17)x10(-2), respectively. The branching fractions are in agreement with standard model theoretical predictions.
12584275
Study of charmless hadronic B meson decays to pseudoscalar-vector final states.
We report results of searches for charmless hadronic B meson decays to pseudoscalar( pi(+/-), K+/-, pi(0), or K(0)(S))-vector( rho, K(*), or omega) final states. By using 9.7x10(6) BB pairs collected with the CLEO detector, we report the first observation of B(-)--->pi(-)rho(0), B(0)-->pi(+/-)rho(-/+), and B(-)-->pi(-)omega, which are expected to be dominated by hadronic b-->u transitions. The measured branching fractions are (10.4(+3.3)(-3.4)+/-2.1)x10(-6), (27.6(+8.4)(-7.4)+/-4.2)x10(-6), and (11.3(+3.3)(-2.9)+/-1. 4)x10(-6), respectively. Branching fraction upper limits are set for all of the other decay modes investigated.
117035924
Measurement of B (tau- ---> tau-neutrino K- K0) and b (tau- ---> tau-neutrino K- K0 pi0)
34604877
Measurement of Cabibbo-suppressed decays of the tau lepton.
Branching ratios for the dominant Cabibbo-suppressed decays of the [tau] lepton have been measured by CLEO II in [ital e][sup +][ital e][sup [minus]] annihilation at the Cornell Electron Storage Ring ([radical][ital s] [similar to]10.6 GeV) using kaons with momenta below 0.7 GeV/[ital c]. The inclusive branching ratio into one charged kaon is (1.60[plus minus]0.12[plus minus]0.19)%. For the exclusive decays, [ital B]([tau][sup [minus]][r arrow][ital K][sup [minus]][nu][sub [tau]])=(0.66[plus minus]0.07[plus minus]0.09)%, [ital B]([tau][sup [minus]][r arrow][ital K][sup [minus]][pi][sup 0][nu][sub [tau]])=(0.51 [plus minus]0.10[plus minus]0.07)%, and, based on three events, [ital B]([tau][sup [minus]][r arrow][ital K][sup [minus]]2[pi][sup 0][nu][sub [tau]])[lt]0.3% at the 90% confidence level. These represent significant improvements over previous results. [ital B]([tau][sup [minus]][r arrow][ital K][sup [minus]][pi][sup 0][nu][sub [tau]]) is measured for the first time with exclusive [pi][sup 0] reconstruction.
181671081
Search for B ---> K lepton+ lepton- and B ---> K* lepton+ lepton- decays
120325427
First results from VERITAS
Abstract VERITAS is an array of four, 12-m-diameter, Cherenkov telescopes, designed to explore the very-high-energy gamma-ray sky in the energy band between 100 GeV and 50 TeV. Its construction and commissioning have occurred over the past two years and the array has been taking scientific data with three or more telescopes since November 2006. We present results from observations made with VERITAS during the past observing season, including new results on the distant blazar 1ES 1218 + 304 , the active galaxy M87 and the high-mass X-ray binary system LS I + 61 303. We also describe the plans in place for the coming observing seasons.
42542272
A Search for Dark Matter Annihilation with the Whipple 10 m Telescope
We present observations of the dwarf galaxies Draco and Ursa Minor, the Local Group galaxies M32 and M33, and the globular cluster M15 conducted with the Whipple 10 m gamma-ray telescope to search for the gamma-ray signature of self-annihilating weakly interacting massive particles (WIMPs), which may constitute astrophysical dark matter (DM). We review the motivations for selecting these sources based on their unique astrophysical environments and report the results of the data analysis that produced upper limits on the excess rate of gamma rays for each source. We consider models for the DM distribution in each source based on the available observational constraints and discuss possible scenarios for the enhancement of the gamma-ray luminosity. Limits on the thermally averaged product of the total self-annihilation cross section and velocity of the WIMP, -->?? , are derived using conservative estimates for the magnitude of the astrophysical contribution to the gamma-ray flux. Although these limits do not constrain predictions from the currently favored theoretical models of supersymmetry (SUSY), future observations with VERITAS will probe a larger region of the WIMP parameter phase space, -->?? , and WIMP particle mass ( -->m?).
53548901
VERITAS OBSERVATIONS OF THE UNUSUAL EXTRAGALACTIC TRANSIENT SWIFT J164449.3+573451
We report on very high energy (>100 GeV) gamma-ray observations of Swift J164449.3+573451, an unusual transient object first detected by the Swift Observatory and later detected by multiple radio, optical, and X-ray observatories. A total exposure of 28 hr was obtained on Swift J164449.3+573451 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) during 2011 March 28-April 15. We do not detect the source and place a differential upper limit on the emission at 500 GeV during these observations of 1.4 × 10–12 erg cm–2 s–1 (99% confidence level). We also present time-resolved upper limits and use a flux limit averaged over the X-ray flaring period to constrain various emission scenarios that can accommodate both the radio-through-X-ray emission detected from the source and the lack of detection by VERITAS.
160875766
VERITAS: STATUS AND EARLY RESULTS ∗
Department of Physics and Astronomy, University of California at Los Angeles430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 USAfor the VERITAS CollaborationV.A. Acciari, G. Blaylock, S.M. Bradbury, J.H. Buckley, V. BugaevY. Butt, K.L. Byrum, D.A. Carter-Lewis, O. Celik, A. CesariniL. Ciupik, Y.C.K. Chow, P. Cogan, P. Colin, W. Cui, M.K. DanielC. Dowdall, P. Dowkontt, C. Duke, T. Ergin, A.D. FalconeD.J. Fegan, S.J. Fegan, J.P. Finley, P. Fortin, L.F. Fortson, D. GallK. Gibbs, G. Gillanders, J. Grube, R. Guenette, G. Gyuk, D. HannaE. Hays, J. Holder, D. Horan, S.B. Hughes, C.M. Hui, T.B. HumenskyA. Imran, P. Kaaret, G.E. Kenny, M. Kertzman, D. Kieda, J. KildeaA. Konopelko, H. Krawczynski, F. Krennrich, M.J. Lang, S. LebohecK. Lee, G. Maier, H. Manseri, A. McCann, M. McCutcheon, J. MillisP. Moriarty, R. Mukherjee, T. Nagai, J. Niemiec, P.A. OgdenR.A. Ong, D. Pandel, J.S. Perkins, F. Pizlo, M. Pohl, J. QuinnK. Ragan, P.T. Reynolds, E. Roache, H.J. Rose, M. SchroedterG.H. Sembroski, A.W. Smith, D. Steele, S.P. Swordy, A. SysonJ.A. Toner, L. Valcarcel, V.V. Vassiliev, R. Wagner, S.P. WakelyJ.E. Ward, T.C. Weekes, A. Weinstein, R.J. White, D.A. WilliamsS.A. Wissel, M. Wood, B. Zitzerhttp://veritas.sao.arizona.edu
121794904
A universal phase space for particles in Yang-Mills fields
Given a principal G-bundle P over M and a Hamiltonian G-space Q, one may construct the reduced symplectic manifold (T*P x Q)0. When a connection on P is chosen, this manifold becomes a bundle over T*M with fibre Q. It is shown that this bundle is precisely the phase space constructed by Sternberg for a classical particle in a Yang-Mills field.