14,387 research outputs found

    Note on recent measurements of the \psi(1S)\to\ga \eta_C(1S) and \psi(2S)\to\ga \eta_C(1S) branching ratios

    Full text link
    Recently published measurements of the branching ratios {\cal B}(\psi(1S)\to\ga \eta_C(1S)) and {\cal B}(\psi(2S)\to\ga \eta_C(1S)) by the CLEO collaboration are examined in the context of a potential model that includes both relativistic and one-loop QCD corrections to the quark-antiquark interaction. The prediction for the width \Gamma(\psi(1S)\to\ga \eta_C(1S)) is in excellent agreement with the new data but the prediction for \Gamma(\psi(2S)\to\ga \eta_C(1S)) is too small. In an effort to understand this discrepancy, we derive an upper bound on \Gamma(\psi(2S)\to\ga \eta_C(1S)) and point out its experimental value saturates this bound.Comment: Corrected typos, addeded referenc

    Significant Range Extension of \u3ci\u3eLeptotes Marina\u3c/i\u3e (Lepidoptera: Lycaenidae) Into New York State

    Get PDF
    (excerpt) The Marine Blue, Leptotes marina (Reakirt) (Lepidoptera: Lycaenidae), is resident from the southwestern United States south through Mexico to Guatemala, with strays reported no further northeast than extreme northwestern Indiana and extreme south-central Ohio (Opler and Krizek 1984, Scott 1986, Shull 1987, Opler and Maliku 11992, Parshall 1993). Although L. marina may be easily overlooked in the field (Iftner, Shuey and Calhoun 1992), the paucity of published records, e.g., two in Illinois (Irwin and Downey 1973), one in Indiana (Shull 1987), and one in Ohio (Parshall 1993), may truly reflect the rarity of strays in the northeastern portion of its range

    Recent developments in the modeling of heavy quarkonia

    Full text link
    We examine the spectra and radiative decays of the cc-bar and bb-bar systems using a model which incorporates the complete one-loop spin-dependent perturbative QCD short distance potential, a linear confining term including (spin-dependent) relativistic corrections to order v^2/c^2, and a fully relativistic treatment of the kinetic energy. We compare the predictions of this model to experiments, including states and decays recently measured at Belle, BaBar, CLEO and CDF.Comment: 3 pages, contribution to PANIC05, Santa Fe, NM October 200

    Aerobic stability of heat and orchardgrass round-bale silage

    Get PDF
    In Arkansas, silage is typically stored as balage in long rows of round bales wrapped in plastic film. It is important to evaluate the aerobic stability of this fermented forage when it is exposed to air, especially during the winter months when most of it is fed to livestock or sold as a cash crop. Two types of forage, orchardgrass (Dactylis glomerata) and wheat (Triticum aestivum), were harvested in May 2002 and stored as balage. Twenty-one bales of each balage type were unwrapped and exposed to air on 10 Dec. 2002 for 0, 2, 4, 8, 16, 24, or 32 d to evaluate aerobic stability. For both orchardgrass and wheat balage, final bale weight, dry matter (DM) content, and pH were not affected (P \u3e 0.05) by exposure time. Across both balage types, DM recoveries were ≥97% for all bales, indicating that both types of balage were very stable when exposed to air. Concentrations of neutral detergent fiber (NDF) and 48-h ruminal in situ digestibility were not affected (P \u3e 0.05) by exposure time for either balage type. Concentrations of N were greater (P = 0.045) for orchardgrass balage exposed to air for 16 d or longer compared to balage sampled at exposure (d 0), but this response was not observed (P \u3e 0.05) for wheat balage. These results suggest that the balage evaluated in this trial was very stable after exposure to air for up to 32 d. This should allow for considerable flexibility with respect to feeding, transport, and marketing of balage during winter months without significant aerobic deterioration

    Removing sky contributions from SCUBA data

    Full text link
    The Submillimetre Common-User Bolometer Array (SCUBA) is a new continuum camera operating on the James Clerk Maxwell Telescope (JCMT) on Mauna Kea, Hawaii. It consists of two arrays of bolometric detectors; a 91 pixel 350/450 micron array and a 37 pixel 750/850 micron array. Both arrays can be used simultaneously and have a field-of-view of approximately 2.4 arcminutes in diameter on the sky. Ideally, performance should be limited solely by the photon noise from the sky background at all wavelengths of operation. However, observations at submillimetre wavelengths are hampered by ``sky-noise'' which is caused by spatial and temporal fluctuations in the emissivity of the atmosphere above the telescope. These variations occur in atmospheric cells that are larger than the array diameter, and so it is expected that the resultant noise will be correlated across the array and, possibly, at different wavelengths. In this paper we describe our initial investigations into the presence of sky-noise for all the SCUBA observing modes, and explain our current technique for removing it from the data.Comment: 11 pages, 16 figures, Proc SPIE vol 335

    Transformation of two and three-dimensional regions by elliptic systems

    Get PDF
    Grid smoothing and orthogonalization procedures were developed and implemented in the construction of two and three dimensional grids. The procedures are based on the variational methods of grid generation. The two-dimensional examples were computed using the MSU IRIS Graphics Workstation. It was demonstrated that the elliptic grid generation equations, with arbitrary forcing functions, can be solved, in their variational formulation, using a gradient method. Since gradient methods have a global convergence property, the divergence problems often encountered when using SOR iterative methods can be avoided. It is not to be concluded, however, that SOR methods should be abandoned, since gradient methods tend to converge very slowly. In fact, slow convergence was the major problem encountered in the three-dimensional grids. Further progress was made on the continuing effort to develop conservative interpolation formulas for overlapping grids

    Testing Portfolio Efficiency with Conditioning Information

    Get PDF
    We develop asset pricing models' implications for portfolio efficiency when there is conditioning information in the form of a set of lagged instruments. A model of expected returns identifies a portfolio that should be minimum variance efficient with respect to the conditioning information. Our tests refine previous tests of portfolio efficiency, using the conditioning information optimally. We reject the efficiency of all static or time-varying combinations of the three Fama-French (1996) factors with respect to the conditioning information and also the conditional efficiency of time-varying combinations of the factors, given standard lagged instruments.
    corecore