123430113
Study of flavor-tagged baryon production in B decay
R. Ammar, 1 P. Baringer, 1 A. Bean, 1 D. Besson, 1 D. Coppage, 1 N. Copty, 1 R. Davis, 1 N. Hancock, 1 S. Kotov, 1 I. Kravchenko, 1 N. Kwak, 1 Y. Kubota, 2 M. Lattery, 2 J. K. Nelson, 2 S. Patton, 2 R. Poling, 2 T. Riehle, 2 V. Savinov, 2 R. Wang, 2 M. S. Alam, 3 I. J. Kim, 3 Z. Ling, 3 A. H. Mahmood, 3 J. J. O’Neill, 3 H. Severini, 3 C. R. Sun, 3 S. Timm, 3 F. Wappler, 3 G. Crawford, 4 J. E. Duboscq, 4 R. Fulton, 4 D. Fujino, 4 K. K. Gan, 4 K. Honscheid, 4 H. Kagan, 4 R. Kass, 4 J. Lee, 4 M. Sung, 4 C. White, 4 R. Wanke, 4 A. Wolf, 4 M. M. Zoeller, 4 X. Fu, 5 B. Nemati, 5 W. R. Ross, 5 P. Skubic, 5 M. Wood, 5 M. Bishai, 6 J. Fast, 6 E. Gerndt, 6 J. W. Hinson, 6 T. Miao, 6 D. H. Miller, 6 M. Modesitt, 6 E. I. Shibata, 6 I. P. J. Shipsey, 6 P. N. Wang, 6 L. Gibbons, 7 S. D. Johnson, 7 Y. Kwon, 7 S. Roberts, 7 E. H. Thorndike, 7 T. E. Coan, 8 J. Dominick, 8 V. Fadeyev, 8 I. Korolkov, 8 M. Lambrecht, 8 S. Sanghera, 8 V. Shelkov, 8 R. Stroynowski, 8 I. Volobouev, 8 G. Wei, 8 M. Artuso, 9 M. Gao, 9 M. Goldberg, 9 D. He, 9 N. Horwitz, 9 S. Kopp, 9 G. C. Moneti, 9 R. Mountain, 9 F. Muheim, 9 Y. Mukhin, 9 S. Playfer, 9 T. Skwarnicki, 9 S. Stone, 9 X. Xing, 9 J. Bartelt, 10 S. E. Csorna, 10 V. Jain, 10 S. Marka, 10 D. Gibaut, 11 K. Kinoshita, 11 P. Pomianowski, 11 S. Schrenk, 11 B. Barish, 12 M. Chadha, 12 S. Chan, 12 D. F. Cowen, 12 G. Eigen, 12 J. S. Miller, 12 C. O’Grady, 12 J. Urheim, 12 A. J. Weinstein, 12 F. Wurthwein, 12 D. M. Asner, 13 M. Athanas, 13 D. W. Bliss, 13 W. S. Brower, 13 G. Masek, 13 H. P. Paar, 13 J. Gronberg, 14 C. M. Korte, 14 R. Kutschke, 14 S. Menary, 14 R. J. Morrison, 14 S. Nakanishi, 14 H. N. Nelson, 14 T. K. Nelson, 14 C. Qiao, 14 J. D. Richman, 14 D. Roberts, 14 A. Ryd, 14 H. Tajima, 14 M. S. Witherell, 14 R. Balest, 15 K. Cho, 15 W. T. Ford, 15 M. Lohner, 15 H. Park, 15 P. Rankin, 15 J. Roy, 15 J. G. Smith, 15 J. P. Alexander, 16 C. Bebek, 16 B. E. Berger, 16 K. Berkelman, 16 K. Bloom, 16 T. E. Browder, 16,* D. G. Cassel, 16 H. A. Cho, 16 D. M. Coffman, 16 D. S. Crowcroft, 16 M. Dickson, 16 P. S. Drell, 16 D. J. Dumas, 16 R. Ehrlich, 16 R. Elia, 16 P. Gaidarev, 16 B. Gittelman, 16 S. W. Gray, 16 D. L. Hartill, 16 B. K. Heltsley, 16 S. Henderson, 16 C. D. Jones, 16 S. L. Jones, 16 J. Kandaswamy, 16 N. Katayama, 16 P. C. Kim, 16 D. L. Kreinick, 16 T. Lee, 16 Y. Liu, 16 G. S. Ludwig, 16 J. Masui, 16 J. Mevissen, 16 N. B. Mistry, 16 C. R. Ng, 16 E. Nordberg, 16 J. R. Patterson, 16 D. Peterson, 16 D. Riley, 16 A. Soffer, 16 C. Ward, 16 P. Avery, 17 A. Freyberger, 17 K. Lingel, 17 C. Prescott, 17 J. Rodriguez, 17 S. Yang, 17 J. Yelton, 17 G. Brandenburg, 18 D. Cinabro, 18 T. Liu, 18 M. Saulnier, 18 R. Wilson, 18 H. Yamamoto, 18 T. Bergfeld, 19 B. I. Eisenstein, 19 J. Ernst, 19 G. E. Gladding, 19 G. D. Gollin, 19 M. Palmer, 19 M. Selen, 19 J. J. Thaler, 19 K. W. Edwards, 20 K. W. McLean, 20 M. Ogg, 20 A. Bellerive, 21 D. I. Britton, 21 E. R. F. Hyatt, 21 R. Janicek, 21 D. B. MacFarlane, 21 P. M. Patel, 21 B. Spaan, 21 and A. J. Sadoff 22 ~CLEO Collaboration!
181671081
Search for B ---> K lepton+ lepton- and B ---> K* lepton+ lepton- decays
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.
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.
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.
117035924
Measurement of B (tau- ---> tau-neutrino K- K0) and b (tau- ---> tau-neutrino K- K0 pi0)
14521638
Veritas observations of gamma-ray bursts detected by swift
We present the results of 16 Swift-triggered Gamma-ray burst (GRB) follow-up observations taken with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) telescope array from 2007 January to 2009 June. The median energy threshold and response time of these observations were 260 GeV and 320 s, respectively. Observations had an average duration of 90 minutes. Each burst is analyzed independently in two modes: over the whole duration of the observations and again over a shorter timescale determined by the maximum VERITAS sensitivity to a burst with a t –1.5 time profile. This temporal model is characteristic of GRB afterglows with high-energy, long-lived emission that have been detected by the Large Area Telescope on board the Fermi satellite. No significant very high energy (VHE) gamma-ray emission was detected and upper limits above the VERITAS threshold energy are calculated. The VERITAS upper limits are corrected for gamma-ray extinction by the extragalactic background light and interpreted in the context of the keV emission detected by Swift. For some bursts the VHE emission must have less power than the keV emission, placing constraints on inverse Compton models of VHE emission.
17735409
Evidence for long-term gamma-ray and x-ray variability from the unidentified TeV source HESS J0632+057
HESS J0632+057 is one of only two unidentified very-high-energy gamma-ray sources which appear to be point-like within experimental resolution. It is possibly associated with the massive Be star MWC 148 and has been suggested to resemble known TeV binary systems like LS I +61 303 or LS 5039. HESS J0632+057 was observed by VERITAS for 31 hr in 2006, 2008, and 2009. During these observations, no significant signal in gamma rays with energies above 1?TeV was detected from the direction of HESS J0632+057. A flux upper limit corresponding to 1.1% of the flux of the Crab Nebula has been derived from the VERITAS data. The nondetection by VERITAS excludes with a probability of 99.993% that HESS J0632+057 is a steady gamma-ray emitter. Contemporaneous X-ray observations with the Swift X-Ray Telescope reveal a factor of 1.8 ? 0.4 higher flux in the 1-10?keV range than earlier X-ray observations of HESS J0632+057. The variability in the gamma-ray and X-ray fluxes supports interpretation of the object as a gamma-ray emitting binary.
118589431
TeV and Multi-wavelength Observations of Mrk?421 in 2006-2008
We report on TeV γ-ray observations of the blazar Mrk 421 (redshift of 0.031) with the VERITAS observatory and the Whipple 10 m Cherenkov telescope. The excellent sensitivity of VERITAS allowed us to sample the TeV γ-ray fluxes and energy spectra with unprecedented accuracy where Mrk 421 was detected in each of the pointings. A total of 47.3 hr of VERITAS and 96 hr of Whipple 10 m data were acquired between 2006 January and 2008 June. We present the results of a study of the TeV γ-ray energy spectra as a function of time and for different flux levels. On 2008 May 2 and 3, bright TeV γ-ray flares were detected with fluxes reaching the level of 10 Crab. The TeV γ-ray data were complemented with radio, optical, and X-ray observations, with flux variability found in all bands except for the radio wave band. The combination of the Rossi X-ray Timing Explorer and Swift X-ray data reveal spectral hardening with increasing flux levels, often correlated with an increase of the source activity in TeV γ-rays. Contemporaneous spectral energy distributions were generated for 18 nights, each of which are reasonably described by a one-zone synchrotron self-Compton model.
17051380
Multiwavelength observations of a TeV-Flare from W comae
We report results from an intensive multiwavelength campaign on the intermediate-frequency-peaked BL Lacertae object W Com (z = 0.102) during a strong outburst of very high energy gamma-ray emission in 2008 June. The very high energy gamma-ray signal was detected by VERITAS on 2008 June 7-8 with a flux F(>200 GeV) =(5.7 ± 0.6) × 10–11 cm–2 s–1, about three times brighter than during the discovery of gamma-ray emission from W Com by VERITAS in 2008 March. The initial detection of this flare by VERITAS at energies above 200 GeV was followed by observations in high-energy gamma rays (AGILE; E γ≥ 100 MeV), X-rays (Swift and XMM-Newton), and at UV, and ground-based optical and radio monitoring through the GASP-WEBT consortium and other observatories. Here we describe the multiwavelength data and derive the spectral energy distribution of the source from contemporaneous data taken throughout the flare.
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