550 research outputs found

    Inclusive Muon Capture in Light Nuclei

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    We study total muon capture rates in light nuclei, taking into account renormalizations of the nuclear vector and axial vector strengths. We estimate the influence in the results of uncertainties of the spin-isospin interaction parameter and nuclear densities. A few of these reactions are theoretical benchmarks for physics involving searches for neutrino oscillations. New experiments in muon capture in several targets are suggested, in the light of some discrepancies with theory, crudeness of some experimental results and relevance to neutrino physics.Comment: 11 pages, Latex, no figures. Submitted to Phys.Lett.

    Indirect Evidences of Wildlife Activities in Shoals of Western Ghats, a Biodiversity Hotspots

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    The presence of wildlife fauna and its activities were ascertained with the density of the scat, dung and other markings or droppings of the wildlife abode therein. Attempt was made to find out spatial differences in the activities of the wildlife populations and to comment on the abundance of different preys and predators within shola forests of Western Ghat hill forests, a Biodiversity hotspot in India. An indirect sampling method, Transect Count Method, was employed to count dung/pellet group/scat and other markings in that area. Pachyderms were found to be mostly dominant in Varagaliar and Punnumala shola patches while scats of all the three important predators, viz., tiger (Panthera tigris tigris), Indian wild dog (Cuon alpinus) and leopard (Panthera pardus) were encountered only in Varagaliar shola. Greater abundance was recorded from Indira Gandhi Wildlife Sanctuary than Silent Valley National Park may be because of the restriction of animal movements in the former due to topographical barriers and its existence as isolated shola patches that led to a greater concentration of wild fauna in a relatively segregated forest coverΠŸΡ€ΠΈΡΡƒΡ‚ΡΡ‚Π²ΠΈΠ΅ ΠΎΡ€Π³Π°Π½ΠΈΠ·ΠΌΠΎΠ² Π² ΠΏΡ€ΠΈΡ€ΠΎΠ΄Π½ΠΎΠΉ срСдС ΠΈ ΠΈΡ… ΠΆΠΈΠ·Π½Π΅Π΄Π΅ΡΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΡŒ Π±Ρ‹Π»ΠΈ установлСны ΠΏΠΎ плотности распрСдСлСния экскрСмСнтов ΠΈ Π΄Ρ€ΡƒΠ³ΠΈΡ… ΠΌΠ΅Ρ‚ΠΎΠΊ ΠΆΠΈΠ²ΠΎΡ‚Π½Ρ‹Ρ… Π² исслСдованных мСстах. Π‘Ρ‹Π»ΠΈ сдСланы ΠΏΠΎΠΏΡ‹Ρ‚ΠΊΠΈ Π½Π°ΠΉΡ‚ΠΈ отличия Π² ΠΆΠΈΠ·Π½Π΅Π΄Π΅ΡΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ популяций Π΄ΠΈΠΊΠΈΡ… ΠΆΠΈΠ²ΠΎΡ‚Π½Ρ‹Ρ…, ΠΈ ΠΏΡ€ΠΎΠΊΠΎΠΌΠΌΠ΅Π½Ρ‚ΠΈΡ€ΠΎΠ²Π°Ρ‚ΡŒ ΠΌΠ½ΠΎΠ³ΠΎΠΎΠ±Ρ€Π°Π·ΠΈΠ΅ Ρ…ΠΈΡ‰Π½ΠΈΠΊΠΎΠ² ΠΈ ΠΈΡ… ΠΆΠ΅Ρ€Ρ‚Π² Π² лСсах шола, мСстах наибольшСго биоразнообразия Π² Индии. ΠœΠ΅Ρ‚ΠΎΠ΄ косвСнных ΠΎΠ±Ρ€Π°Π·Ρ†ΠΎΠ² ΠΈ ΠΌΠ΅Ρ‚ΠΎΠ΄ трансСктного подсчСта Π±Ρ‹Π»ΠΈ ΠΈΡΠΏΠΎΠ»ΡŒΠ·ΠΎΠ²Π°Π½Ρ‹ для подсчСта экскрСмСнтов/ΠΏΠΎΠ³Π°Π΄ΠΎΠΊ ΠΈ Π΄Ρ€ΡƒΠ³ΠΈΡ… ΠΌΠ΅Ρ‚ΠΎΠΊ Π² исслСдуСмом Ρ€Π΅Π³ΠΈΠΎΠ½Π΅. УстановлСно, Ρ‡Ρ‚ΠΎ Π½Π° Π½Π΅Π±ΠΎΠ»ΡŒΡˆΠΈΡ… участках Π·Π΅ΠΌΠ»ΠΈ Π² шола Π’Π°Ρ€Π°Π³Π°Π»ΠΈΠ°Ρ€ ΠΈ ΠŸΡƒΠ½Π½ΡƒΠΌΠ°Π»Π° Π΄ΠΎΠΌΠΈΠ½ΠΈΡ€ΡƒΡŽΡ‚ толстокоТиС, Ρ‚ΠΎΠ³Π΄Π° ΠΊΠ°ΠΊ экскрСмСнты Ρ…ΠΈΡ‰Π½ΠΈΠΊΠΎΠ² – Ρ‚ΠΈΠ³Ρ€Π° (Panthera tigris tigris), красного Π²ΠΎΠ»ΠΊΠ° (Cuon alpinus) ΠΈ Π»Π΅ΠΎΠΏΠ°Ρ€Π΄Π° (Panthera pardus) – Π±Ρ‹Π»ΠΈ случайно ΠΎΠ±Π½Π°Ρ€ΡƒΠΆΠ΅Π½Ρ‹ Ρ‚ΠΎΠ»ΡŒΠΊΠΎ Π² шола Π’Π°Ρ€Π°Π³Π°Π»ΠΈΠ°Ρ€. Π—Π½Π°Ρ‡ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎ большСС количСство Π±Ρ‹Π»ΠΎ зарСгистрировано Π² Π—Π°ΠΏΠΎΠ²Π΅Π΄Π½ΠΈΠΊΠ΅ Π΄ΠΈΠΊΠΎΠΉ ΠΏΡ€ΠΈΡ€ΠΎΠ΄Ρ‹ ΠΈΠΌ. Π˜Π½Π΄ΠΈΡ€Ρ‹ Π“Π°Π½Π΄ΠΈ ΠΏΠΎ ΡΡ€Π°Π²Π½Π΅Π½ΠΈΡŽ с ΠΠ°Ρ†ΠΈΠΎΠ½Π°Π»ΡŒΠ½Ρ‹ΠΌ ΠΏΠ°Ρ€ΠΊΠΎΠΌ «Вихая Π”ΠΎΠ»ΠΈΠ½Π°Β», Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎ, ΠΈΠ·-Π·Π° ограничСния ΠΌΠΈΠ³Ρ€Π°Ρ†ΠΈΠΉ ΠΆΠΈΠ²ΠΎΡ‚Π½Ρ‹Ρ… топографичСскими Π±Π°Ρ€ΡŒΠ΅Ρ€Π°ΠΌΠΈ Π² ΠΏΡ€ΠΎΡˆΠ»ΠΎΠΌ, Ρ‡Ρ‚ΠΎ ΠΏΡ€ΠΈΠ²Π΅Π»ΠΎ ΠΊ большСй ΠΊΠΎΠ½Ρ†Π΅Π½Ρ‚Ρ€Π°Ρ†ΠΈΠΈ Π΄ΠΈΠΊΠΎΠΉ Ρ„Π°ΡƒΠ½Ρ‹ Π² ΠΎΡ‚Π½ΠΎΡΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎ обособлСнном лСсу

    Measurement of the Interior Structure of Thin Polymer Films Using Grazing Incidence Diffuse X-Ray Scattering

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    A method is developed for calculating the small-angle x-ray scattering originating from within the interior of a thin film under grazing incidence illumination. This offers the possibility of using x-ray scattering to probe how the structure of polymers is modified by confinement. When the diffuse scattering from a thin film is measured over a range of incident angles, it is possible to separate the contributions to scattering from the interfaces and the contribution from the film interior. Using the distorted-wave Born approximation the structure factor, S q , of the film interior can then be obtained. We apply this method to analyze density fluctuations from within the interior of a silicon supported molten polystyrene PS film. Measurements were made as a function of film thickness ranging from one to ten times the polymer radius of gyration Rg . The compressibility, calculated by extrapolating the measured S q to q=0, agrees well with that of bulk PS for thick films, but thinner films exhibit a peak in S q near q=0. This peak, which grows with decreasing thickness, is attributed to a decreased interpenetration of chains and a consequent enhanced compressibility.This work is supported by NSF Grant No. DMR-0209542. Use of the Advanced Photon Source at Argonne National Laboratory was supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under DOE Contract No. DE-AC02-06CH11357

    Stochastic dynamic stability analysis of composite curved panels subjected to non-uniform partial edge loading

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    The stochastic dynamic stability analysis of laminated composite curved panels under non-uniform partial edge loading is studied using finite element analysis. The system input parameters are randomized to ascertain the stochastic first buckling load and zone of resonance. Considering the effects of transverse shear deformation and rotary inertia, first order shear deformation theory is used to model the composite doubly curved shells. The stochasticity is introduced in Love's and Donnell's theory considering dynamic and shear deformable theory according to the Sander's first approximation by tracers for doubly curved laminated shells. The moving least square method is employed as a surrogate of the actual finite element model to reduce the computational cost. The results are compared with those available in the literature. Statistical results are presented to show the effects of radius of curvatures, material properties, fibre parameters, and non-uniform load parameters on the stability boundaries

    Spin 0 and spin 1/2 particles in a spherically symmetric static gravity and a Coulomb field

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    A relativistic particle in an attractive Coulomb field as well as a static and spherically symmetric gravitational field is studied. The gravitational field is treated perturbatively and the energy levels are obtained for both spin 0 (Klein-Gordon) and spin 1/2 (Dirac) particles. The results are shown to coincide with each other as well as the result of the nonrelativistic (Schrodinger) equation in the nonrelativistic limit.Comment: 12 page

    Ξ½dβ†’ΞΌβˆ’Ξ”++n\nu d \to \mu^- \Delta^{++} n Reaction and Axial Vector Nβˆ’Ξ”N-\Delta Coupling

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    The reaction Ξ½dβ†’ΞΌβˆ’Ξ”++n\nu d \to \mu^- \Delta^{++} n is studied in the region of low q2q^2 to investigate the effect of deuteron structure and width of the Ξ”\Delta resonance on the differential cross section. The results are used to extract the axial vector Nβˆ’Ξ”N-\Delta coupling C5AC^{A}_5 from the experimental data on this reaction. The possibility to determine this coupling from electroweak interaction experiments with high intensity electron accelerators is discussed.Comment: 14 pages, REVTEX, 5 figure

    Fractional two-branes, toric orbifolds and the quantum McKay correspondence

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    We systematically study and obtain the large-volume analogues of fractional two-branes on resolutions of orbifolds C^3/Z_n. We study a generalisation of the McKay correspondence proposed in hep-th/0504164 called the quantum McKay correspondence by constructing duals to the fractional two-branes. Details are explicitly worked out for two examples -- the crepant resolutions of C^3/Z_3 and C^3/Z_5.Comment: 34 pages, 2 figures, LaTeX (JHEP3 style); (v2) typos corrected; (v3) sec 3 reorganise

    Fractional Branes in Non-compact Type IIA Orientifolds

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    We study fractional D-branes in the Type-IIA theory on a non-compact orientifold of the orbifold C^3/Z_3 in the boundary state formalism. We find that the fractional D0-branes of the orbifold theory become unstable due to the presence of a tachyon, while there is a stable D-instanton whose tachyon gets projected out. We propose that the D-instanton is obtained after tachyon condensation. We evidence this by calculating the Whitehead group of the Abelian category of objects corresponding to the boundary states as being isomorphic to Z_2.Comment: 29 pages, Latex2e minor corrections. references updated. Version accepted in JHE

    A quantum McKay correspondence for fractional 2p-branes on LG orbifolds

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    We study fractional 2p-branes and their intersection numbers in non-compact orbifolds as well the continuation of these objects in Kahler moduli space to coherent sheaves in the corresponding smooth non-compact Calabi-Yau manifolds. We show that the restriction of these objects to compact Calabi-Yau hypersurfaces gives the new fractional branes in LG orbifolds constructed by Ashok et. al. in hep-th/0401135. We thus demonstrate the equivalence of the B-type branes corresponding to linear boundary conditions in LG orbifolds, originally constructed in hep-th/9907131, to a subset of those constructed in LG orbifolds using boundary fermions and matrix factorization of the world-sheet superpotential. The relationship between the coherent sheaves corresponding to the fractional two-branes leads to a generalization of the McKay correspondence that we call the quantum McKay correspondence due to a close parallel with the construction of branes on non-supersymmetric orbifolds. We also provide evidence that the boundary states associated to these branes in a conformal field theory description corresponds to a sub-class of the boundary states associated to the permutation branes in the Gepner model associated with the LG orbifold.Comment: LaTeX2e, 1+39 pages, 3 figures (v2) refs added, typos and report no. correcte
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