1,798,494 research outputs found

    Three-Loop Contribution to Hyperfine Splitting in Muonium: Polarization Corrections to Light by Light Scattering Blob

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    We calculate corrections of order α3(Zα)EF\alpha^3(Z\alpha)E_F to hyperfine splitting in muonium generated by the gauge invariant set of diagrams with polarization insertions in the light by light scattering diagrams. This nonrecoil contribution turns out to be -2.63 Hz. The total contribution of all known corrections of order α3(Zα)EF\alpha^3(Z\alpha)E_F is equal to -4.28 Hz.Comment: 12 pages, 3 figure

    A New Class of Path Equations in AP-Geometry

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    In the present work, it is shown that, the application of the Bazanski approach to Lagrangians, written in AP-geometry and including the basic vector of the space, gives rise to a new class of path equations. The general equation representing this class contains four extra terms, whose vanishing reduces this equation to the geodesic one. If the basic vector of the AP-geometry is considered as playing the role of the electromagnetic potential, as done in a previous work, then the second term (of the extra terms) will represent Lorentz force while the fourth term gives a direct effect of the electromagnetic potential on the motion of the charged particle. This last term may give rise to an effect similar to the Aharanov-Bohm effect. It is to be considered that all extra terms will vanish if the space-time used is torsion-less.Comment: 11 pages, LaTeX fil

    NEW CORRECTIONS OF ORDER α3(Zα)4\alpha^3(Z\alpha)^4 AND α2(Zα)6\alpha^2(Z\alpha)^6 TO THE LAMB SHIFT

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    Two corrections to the Lamb shift, induced by the polarization operator insertions in the external photon lines are calculated.Comment: 4 pages, revtex, no figure

    Radiative-Recoil Corrections to Hyperfine Splitting: Polarization Insertions in the Muon Factor

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    We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium due to insertions of one-loop polarization operator in the muon factor. The contribution produced by electron polarization insertions are enhanced by the large logarithm of the electron-muon mass ratio. We obtained all single-logarithmic and nonlogarithmic radiative-recoil corrections of order α3(m/M)EF\alpha^3(m/M)E_F generated by the diagrams with electron and muon polarization insertions.Comment: 10 pages, 4 figure

    Three-Loop Radiative-Recoil Corrections to Hyperfine Splitting Generated by One-Loop Fermion Factors

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    We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by diagrams with one-loop radiative photon insertions both in the electron and muon lines. An analytic result for these nonlogarithmic corrections of order α(Z2α)(Zα)(m/M)E~F\alpha(Z^2\alpha)(Z\alpha)(m/M)\widetilde E_F is obtained. This result constitutes a next step in the implementation of the program of reduction of the theoretical uncertainty of hyperfine splitting below 10 Hz.Comment: 11 pages, 3 figures, 1 tabl

    Soft and hard processes in QCD

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    QCD equations for the generating functions are applied to separate soft and hard jets in e+ee^+e^--processes of multiparticle production. The dependence of average multiplicities and higher moments of multiplicity distributions of particles created in a "newly born" soft subjets on the share of energy devoted to them is calculated in fixed coupling gluodynamics. This dependence is the same as for the total multiplicity up to a constant factor if soft jets are defined as those carrying out a fixed share of initial energy at all energies. The constant factor depends on this share in a non-trivial way. Other definitions are also proposed. The relation between these quantities for soft and hard processes is discussed.Comment: 6 pages, no Figures, LATEX, more detailed discussion of definitions and proposals for experiment is give

    Lifetimes of Heavy-Flavour Hadrons -- Whence and Whither?

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    A theoretical treatment for the weak decays of heavy-flavour hadrons has been developed that is genuinely based on QCD. Its methodology as it applies to total lifetimes and the underlying theoretical issues are sketched. Predictions are compared with present data. One discrepancy emerges: the beauty baryon lifetime appears to be significantly shorter than expected. The ramifications of those findings are analyzed in detail.Comment: 15 pages, no figures, LATEX, two references added and new information concerning a lower charm content in B decays incorporate

    Electron self-trapping and fluctuation density-of-states tail at the critical point

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    We consider electron self-trapping due to its interaction with order-parameter fluuctuations at the second-order phase-transition or critical point (for example, at the Curie temperature in magnetic or ferroelectric semiconductors). Using Feynman path integral approach the autolocalization energy and the size of the self-trapped state (fluctuon) are estimated. It is shown that the fluctuon states are connected with the Lifshitz tail of the electron density-of-states, the parameters of this tail being determined by the critical exponents.Comment: 4 pages, revtex4, Phys. Rev. B, accepte

    The two types of Cherenkov gluons at LHC energies

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    Beside comparatively low energy Cherenkov gluons observed at RHIC, there could be high energy gluons at LHC, related to the high energy region of positive real part of the forward scattering amplitude. In both cases they give rise to particles emitted along some cone. The characteristics of the cones produced by these two types of gluons are different. Therefore different experiments are needed to detect them. The cosmic ray event which initiated this idea is described in detail.Comment: 6 pages, talk at IWCF2006, Hangzhou, Chin

    High ET_T jets and double scattering

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    The recently found excess of high ET_T jets over current QCD predictions is attributed to gluon radiation at double scattering process inside a nucleon. The order of magnitude estimate of the cross section fits experimental findings rather well. The specific features of the process are discussed. Various similar hadronic effects related to the short radiation length are described.Comment: 6 pages, plain LaTe
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