2,103 research outputs found

    INTEGRATED GEOPHYSICAL INVESTIGATION OF KARST FEATURES – INNER BLUEGRASS REGION OF KENTUCKY

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    High-resolution electrical-resistivity, seismic-refraction, and seismic-reflection surveys were performed at three locations in the Inner Bluegrass Region of Kentucky along coincident survey lines in order to correlate results and determine which method is most effective at locating karst features in this area. The first two survey locations at Slack’s Cave and the Kentucky Horse Park were chosen in order to investigate known karst features. High and low electrical-resistivity anomalies were correlated to air- and water-filled karst voids, respectively. Seismic velocity anomalies, including parabolic time suppressions, amplitude terminations, and surface-wave backscatters, were also observed and correlated to these karst voids. These findings were applied to a third location along Berea Road in order to investigate undiscovered karst voids. Three seismic targets were selected based on backscatter anomaly locations and were aligned in a northwest trend following the general bedrock dip, joint orientations, and suspected conduit orientation. Overall, the seismic-reflection method provided the highest resolution and least ambiguous results; however, integration of multiple methods was determined to help decrease ambiguities in interpretation created by the inherent non-uniqueness found in the results of each method

    Bounds on the slope and the curvature of the scalar K\pi form factor at zero momentum transfer

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    We derive and calculate unitarity bounds on the slope and curvature of the strangeness-changing scalar form factor at zero momentum transfer, using low-energy constraints and Watson final state interaction theorem. The results indicate that the curvature is important and should not be neglected in the representation of experimental data. The bounds can be converted also into an allowed region for the constants C_12rC\_{12}^r and C_34rC\_{34}^r of Chiral Perturbation Theory. Our results are consistent with, but weaker than the predictions made by Jamin, Oller and Pich in a coupled channel dispersion approach basedon chiral resonance model. We comment on the differences between the two dispersive methods and argue that the unitarity bounds are useful as an independent check involving different sources of informationComment: 25 pages, 5 figures, version to be published in Nuclear Physics

    Scalar K pi form factor and light quark masses

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    Recent experimental improvements on K-decay data allow for a precise extraction of the strangeness-changing scalar K pi form factor and the related strange scalar spectral function. On the basis of this scalar as well as the corresponding pseudoscalar spectral function, the strange quark mass is determined to be m_s(2 GeV) = 92 +- 9 MeV. Further taking into account chiral perturbation theory mass ratios, the light up and down quark masses turn out to be m_u(2 GeV) = 2.7 +- 0.4 MeV as well as m_d(2 GeV) = 4.8 +- 0.5 MeV. As a by-product, we also find a value for the Cabibbo angle |V_{us}| = 0.2236(29) and the ratio of meson decay constants F_K/F_\pi = 1.203(16). Performing a global average of the strange mass by including extractions from other channels as well as lattice QCD results yields m_s(2 GeV) = 94 +- 6 MeV.Comment: 5 pages, 2 figures; comparison with lattice and global average added; version to appear in Phys. Rev.

    Precise Determination of |V{us}| from Lattice Calculations of Pseudoscalar Decay Constants

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    Combining the ratio of experimental kaon and pion decay widths, Gamma(K to mu antineutrino{mu} (gamma)) / Gamma(pi to mu \antineutrino (gamma)), with a recent lattice gauge theory calculation of f{K}/f{pi} provides a precise value for the CKM quark mixing matrix element |V{us}|=0.2236(30) or if 3 generation unitarity is assumed |V{us}|=0.2238(30). Comparison with other determinations of that fundamental parameter, implications, and an outlook for future improvements are given

    Corrections to the SU(3)×SU(3){\bf SU(3)\times SU(3)} Gell-Mann-Oakes-Renner relation and chiral couplings L8rL^r_8 and H2rH^r_2

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    Next to leading order corrections to the SU(3)×SU(3)SU(3) \times SU(3) Gell-Mann-Oakes-Renner relation (GMOR) are obtained using weighted QCD Finite Energy Sum Rules (FESR) involving the pseudoscalar current correlator. Two types of integration kernels in the FESR are used to suppress the contribution of the kaon radial excitations to the hadronic spectral function, one with local and the other with global constraints. The result for the pseudoscalar current correlator at zero momentum is ψ5(0)=(2.8±0.3)×103GeV4\psi_5(0) = (2.8 \pm 0.3) \times 10^{-3} GeV^{4}, leading to the chiral corrections to GMOR: δK=(55±5)\delta_K = (55 \pm 5)%. The resulting uncertainties are mostly due to variations in the upper limit of integration in the FESR, within the stability regions, and to a much lesser extent due to the uncertainties in the strong coupling and the strange quark mass. Higher order quark mass corrections, vacuum condensates, and the hadronic resonance sector play a negligible role in this determination. These results confirm an independent determination from chiral perturbation theory giving also very large corrections, i.e. roughly an order of magnitude larger than the corresponding corrections in chiral SU(2)×SU(2)SU(2) \times SU(2). Combining these results with our previous determination of the corrections to GMOR in chiral SU(2)×SU(2)SU(2) \times SU(2), δπ\delta_\pi, we are able to determine two low energy constants of chiral perturbation theory, i.e. L8r=(1.0±0.3)×103L^r_8 = (1.0 \pm 0.3) \times 10^{-3}, and H2r=(4.7±0.6)×103H^r_2 = - (4.7 \pm 0.6) \times 10^{-3}, both at the scale of the ρ\rho-meson mass.Comment: Revised version with minor correction

    Up and down quark masses from Finite Energy QCD sum rules to five loops

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    The up and down quark masses are determined from an optimized QCD Finite Energy Sum Rule (FESR) involving the correlator of axial-vector divergences, to five loop order in Perturbative QCD (PQCD), and including leading non-perturbative QCD and higher order quark mass corrections. This FESR is designed to reduce considerably the systematic uncertainties arising from the (unmeasured) hadronic resonance sector, which in this framework contributes less than 3-4% to the quark mass. This is achieved by introducing an integration kernel in the form of a second degree polynomial, restricted to vanish at the peak of the two lowest lying resonances. The driving hadronic contribution is then the pion pole, with parameters well known from experiment. The determination is done in the framework of Contour Improved Perturbation Theory (CIPT), which exhibits a very good convergence, leading to a remarkably stable result in the unusually wide window s0=1.04.0GeV2s_0 = 1.0 - 4.0 {GeV}^2, where s0s_0 is the radius of the integration contour in the complex energy (squared) plane. The results are: mu(Q=2GeV)=2.9±0.2m_u(Q= 2 {GeV}) = 2.9 \pm 0.2 MeV, md(Q=2GeV)=5.3±0.4m_d(Q= 2 {GeV}) = 5.3 \pm 0.4 MeV, and (mu+md)/2=4.1±0.2(m_u + m_d)/2 = 4.1 \pm 0.2 Mev (at a scale Q=2 GeV).Comment: Additional references to lattice QCD results have been adde

    Stringent constraints on the scalar K pi form factor from analyticity, unitarity and low-energy theorems

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    We investigate the scalar K pi form factor at low energies by the method of unitarity bounds adapted so as to include information on the phase and modulus along the elastic region of the unitarity cut. Using at input the values of the form factor at t=0 and the Callan-Treiman point, we obtain stringent constraints on the slope and curvature parameters of the Taylor expansion at the origin. Also, we predict a quite narrow range for the higher order ChPT corrections at the second Callan-Treiman point.Comment: 5 pages latex, uses EPJ style files, 3 figures, replaced with version accepted by EPJ

    Possible explanation of the discrepancy of the light-cone QCD sum rule calculation of g(D*Dpi) coupling with experiment

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    The introduction of an explicit negative radial excitation contribution in the hadronic side of the light cone QCD sum rule (LCSR) of Belyaev, Braun, Khodjamirian and Ruckl, can explain the large experimental value of g(D*Dpi), recently measured by CLEO. At the same time, it considerably improves the stability of the sum rule when varying the Borel parameter.Comment: 9 pages, 1 PostScript figure

    Uji Adaptasi Beberapa Klon Karet pada Elevasi Tinggi

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    Lahan yang ideal untuk pertumbuhan tanaman karet semakin terbatas sehingga banyak petani dan Perusahaan mencari lahan pengembangan karet di daerah non tradisional seperti lahan pada > 500 m di atas permukaan laut (mdpl). Penelitian dilakukan di Kabupaten Muara Enim pada elevasi 760 mdpl. Penelitian bertujuan untuk mendapatkan informasi pertumbuhan dan produksi beberapa klon karet pada elevasi tinggi. Rancangan yang digunakan adalah Rancangan Acak Kelompok dengan klon sebagai perlakuan dan diulang sebanyak empat kali. Klon yang diuji adalah PB 260, RRIC 100, BPM 24, GT 1 dan IRR 39. Hasil penelitian menunjukkan bahwa tanaman karet pada elevasi tinggi dengan perawatan sesuai anjuran akan mampu matang sadap pada umur lima tahun. Pertumbuhan klon karet paling cepat pada elevasi tinggi 760 m dpl secara berurutan adalah IRR 39, RRIC 100, PB 260, BPM 24 dan GT 1, sedangkan produksi paling tinggi adalah PB 260, RRIC 100, BPM 24, GT 1 dan IRR 39
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