118 research outputs found

    The possibility of Z(4430) resonance structure description in πψ\pi\psi' reaction

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    The possible description of Z(4430) as a pseudoresonance structure in πψ\pi \psi' reaction, is considered. The analysis is performed with single-scattering contribution to πψ\pi \psi' elastic scattering via DD1(2420)D^*D_1(2420) intermediate energy.Comment: 3 pages, 4 figure

    Finite element modeling of multiple electrode submerged arc welding of large diameter pipes

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    For the process of multiple-electrode submerged arc welding (MESAW) of large- diameter pipes (LDP) a mathematical model has been developed with a numerical solution in the software product "SYSWELD". The paper defines the parameters of double ellipsoid model of heat sources by J. Goldak. Using regression analysis of experimental data empirical formulas for calculating geometrical parameters of heat sources model by J. Goldak and deposition rate were developed for welding with direct current on positive polarity and alternating current. The model allows to predict the shape of weld and to estimate analytically the cooling rate in the heat affected zone (HAZ). The developed model and its numerical solutions with sufficient accuracy for practical calculations reflect the process of longitudinal welding of LDP. © 2019 IOP Publishing Ltd

    Siberian Roe Deer (Capreolus pygargus Pallas, 1771) in Ukraine: Analysis of the Mitochondrial and Nuclear DNA

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    A molecular-genetic analysis of the nucleotide sequences of the cytochrome b gene (1140 base pairs) of the mitochondrial DNA and 17 microsatellite loci of eight samples of roe deer from the Samara forest of Dnipropetrovsk oblast (Ukraine) was carried out. For comparison, 212 corresponding mtDNA sequences of the Siberian and European roe deer and data on the variability of microsatellite markers in 49 representatives of these species were included in the study. It was noted that all the analyzed mitochondrial sequences of individuals from the Samara forest are characteristic of the Siberian roe Capreolus pygargus Pallas, 1771. Four haplotypes were described, all of which belonged to the haplogroup typical for the western part of the range of C. pygargus. A fragment analysis of the microsatellite loci of nuclear DNA confirmed the identification of the investigated group with the Siberian species

    Khuri-Treiman equations for 3π decays of particles with spin

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    Khuri-Treiman equations have proven to be a useful theoretical tool in the analysis of three-body decays, especially into the 3π final state. In this work we present in full detail the necessary generalization of the formalism to study the decays of particles with arbitrary spin, parity, and charge conjugation. To this extent, we find it most convenient to work with helicity amplitudes instead of the so-called invariant amplitudes, especially when dealing with the unitarity relations. The isobar expansions in the three possible (s-, t-, and u-) final channels are related with the appropriate crossing matrices. We pay special attention to the kinematical singularities and constraints of the helicity amplitudes, showing that these can be derived by means of the crossing matrix

    The SD\mathbf{S}-\mathbf{D} mixing and di-electron widths of higher charmonium 1\mathbf{1^{--}} states

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    The di-electron widths of ψ(4040)\psi(4040), ψ(4160)\psi(4160), and ψ(4415)\psi(4415), and their ratios are shown to be in good agreement with experiment, if in all cases the SDS-D mixing with a large mixing angle θ34\theta\approx 34^\circ is taken. Arguments are presented why continuum states give small contributions to the wave functions at the origin. We find that the Y(4360) resonance, considered as a pure 33D13 {}^3D_1 state, would have very small di-electron width, Γee(Y(4360))=0.060\Gamma_{ee}(Y(4360))=0.060 keV. On the contrary, for large mixing between the 43S14 {}^3S_1 and 33D13 {}^3D_1 states with the mixing angle θ=34.8\theta=34.8^\circ, Γee(ψ(4415))=0.57\Gamma_{ee}(\psi(4415))=0.57 keV coincides with the experimental number, while a second physical resonance, probably Y(4360), has also a rather large Γee(Y(4400))=0.61\Gamma_{ee} (Y(\sim 4400))=0.61 keV. For the higher resonance Y(4660), considered as a pure 53S15 {}^3S_1 state, we predict the di-electron width Γee(Y(4660))=0.70\Gamma_{ee}(Y(4660))=0.70 keV, but it becomes significantly smaller, namely 0.31 keV, if the mixing angle between the 53S15 {}^3S_1 and 43D14 {}^3D_1 states θ=34\theta=34^\circ. The mass and di-electron width of the 63S16 {}^3S_1 charmonium state are calculated.Comment: 19 pages, no figure

    Electromagnetic transitions in an effective chiral Lagrangian with the eta-prime and light vector mesons

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    We consider the chiral Lagrangian with a nonet of Goldstone bosons and a nonet of light vector mesons. The mixing between the pseudoscalar mesons eta and eta-prime is taken into account. A novel counting scheme is suggested that is based on hadrogenesis, which conjectures a mass gap in the meson spectrum of QCD in the limit of a large number of colors. Such a mass gap would justify to consider the vector mesons and the eta-prime meson as light degrees of freedom. The complete leading order Lagrangian is constructed and discussed. As a first application it is tested against electromagnetic transitions of light vector mesons to pseudoscalar mesons. Our parameters are determined by the experimental data on photon decays of the omega, phi and eta-prime meson. In terms of such parameters we predict the corresponding decays into virtual photons with either dielectrons or dimuons in the final state.Comment: 17 pages, extended discussion on mixin
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