8,174 research outputs found

    The processes e+eππ(π)e^{+}e^{-} \to \pi\pi(\pi') in the extended NJL model

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    The process e+eπ+πe^{+}e^{-} \to \pi^{+}\pi^{-} is described in the framework of the extended NJL model. Intermediate vector mesons ρ0(770)\rho^0(770), ω(782)\omega(782) and \rho'(1450)aretakenintoaccount.Ourresultsareinsatisfactoryagreementwithexperimentaldata.Thepredictionfortheprocess are taken into account. Our results are in satisfactory agreement with experimental data. The prediction for the process e^{+}e^{-} \to \pi\pi'(1300)isgiven.Herethemaincontributionisgivenbythediagramwithintermediate is given. Here the main contribution is given by the diagram with intermediate \rho'(1450)$ meson.Comment: 7 pages, 5 figure

    NJL interaction derived from QCD: vector and axial-vector mesons

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    In previous works effective non-local SU(2)×SU(2)SU(2)\times SU(2) NJL model was derived in the framework of the fundamental QCD. All the parameters of the model are expressed through QCD parameters: current light quark mass m0m_0 and average non-perturbative αs\alpha_s. The results for scalar and pseudo-scalar mesons are in satisfactory agreement to existing data. In the present work the same model without introduction of any additional parameters is applied for a description of masses and strong decay widths of ρ\rho- and a1a_1-mesons. The results for both scalar and vector sectors agree with data with only one adjusted parameter m0m_0, with account of average αs0.415\alpha_s \simeq 0.415, which is obtained in a previous work as well.Comment: 19 pages, 2 figures, 1 tabl

    Production of π0ρ0\pi^0\rho^0 pair in electron-positron annihilation in the Nambu-Jona-Lasinio model

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    The process e+eπ0ρe^+e^- \to \pi^0\rho is described in the framework of the expanded NJL model in the energy region from 0.9 GeV to 1.5 GeV. The contribution of intermediate state with vector mesons ω(782),ϕ(1020)\omega(782), \,\,\phi(1020), and ω(1420)\omega'(1420), where ω\omega' is the first radial excitation of ω\omega - meson was taken into account. Results obtained are in satisfactory agreement with experimental data.Comment: 5 pages, 1 figure, 1 tabl

    Parafermions, parabosons and representations of so(\infty) and osp(1|\infty)

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    The goal of this paper is to give an explicit construction of the Fock spaces of the parafermion and the paraboson algebra, for an infinite set of generators. This is equivalent to constructing certain unitary irreducible lowest weight representations of the (infinite rank) Lie algebra so(\infty) and of the Lie superalgebra osp(1|\infty). A complete solution to the problem is presented, in which the Fock spaces have basis vectors labelled by certain infinite but stable Gelfand-Zetlin patterns, and the transformation of the basis is given explicitly. We also present expressions for the character of the Fock space representations

    The Paths of Unification In The GUST With The G x G Gauge Groups of E(8) x E(8)

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    In the framework of the four dimensional heterotic superstring with free fermions we discuss the rank eight and/or sixteen Grand Unified String Theories (GUST) which contain the SU(3)_H - gauge family symmetry. We explicitly investigate the paths of the unification in the GUST with gauge symmetry G x G = [SU(5) x U(1) x (SU(3) x U(1))_H]^2. We show that the GUSTs with the G x G gauge group allow to make the scale of unification to be consistent with the string scale M_SU = g_{string} * 5 * 10^17 GeV.Comment: 18 pages, 2 Postscript figures, uses epsf.st
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