225 research outputs found

    Dynamical quark loop light-by-light contribution to muon g-2 within the nonlocal chiral quark model

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    The hadronic corrections to the muon anomalous magnetic moment a_mu, due to the gauge-invariant set of diagrams with dynamical quark loop light-by-light scattering insertions, are calculated in the framework of the nonlocal chiral quark model. These results complete calculations of all hadronic light-by-light scattering contributions to a_mu in the leading order in the 1/Nc expansion. The result for the quark loop contribution is a_mu^{HLbL,Loop}=(11.0+-0.9)*10^(-10), and the total result is a_mu^{HLbL,NxQM}=(16.8+-1.2)*10^(-10).Comment: 11 pages, 5 figures, 1 tabl

    Transition form factor of γ → 3π in a nonlocal quark model

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    The transition form factor of a gamma into three pions F3π are studied in a framework of nonlocal chiral quark model. In local limit the result is agreement with chiral perturbative theory and reproduce Wess-Zumino-Witten anomaly. Availability of nonlocality not change a value of transition form factor in chiral limit. On the physical threshold of reaction, the transition form factor F3π is obtained close to the experimental data on account of current mass of quark

    Deep inelastic eτe-\tau and μτ\mu-\tau conversion in the NA64 experiment at the CERN SPS

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    We study the Lepton Flavor Violating (LFV) e(μ)τe(\mu)-\tau conversion in Deep Inelastic Scattering (DIS) of electron (muon) on fixed-target nuclei. Our model-independent analysis is based on the set of the low-energy effective four-fermion LFV operators composed of leptons and quarks with the corresponding mass scales Λk\Lambda_{k} for each operator. Using the estimated sensitivity of the search for this LFV process in events with large missing energy in the NA64 experiment at the CERN SPS, we derive lower limits for Λk\Lambda_{k} and compared them with the corresponding limits existing in the literature. We show that the DIS e(μ)τe(\mu)-\tau conversion is able to provide a plenty of new limits as yet non-existing in the literature. We also analyzed the energy spectrum of the final-state τ\tau and discussed viability of the observation of this process in the NA64 experiment and ones akin to it. The case of polarized beams and targets is also discussed.Comment: 18 page

    Free Malcev algebra of rank three

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    We find a basis of the free Malcev algebra on three free generators over a field of characteristic zero. The specialty and semiprimity of this algebra are proved. In addition, we prove the decomposability of this algebra into subdirect sum of the free Lie algebra rank three and the free algebra of rank three of variety of Malcev algebras generated by a simple seven-dimensional Malcev algebra

    Intrinsic multipole moments of non-Gaussian wave packets

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    The charged wave packets with non-Gaussian spatial profiles are shown to possess intrinsic multipole moments. The magnetic dipole moment and the electric quadrupole moment are found for a wide class of the packets, including the vortex electrons with orbital angular momentum ℓ, the Airy beams, the so-called Schrödinger's cat states, and their generalizations. For the packets with no phase vortices, the electric quadrupole moment is shown to grow quadratically with the packet's width, |Qαβ|∼e⋅σ2⊥, while it is also |ℓ| times enhanced for the vortex beams. For available beams of electron microscopes, these multipole moments are relatively easily adjusted and can be quite large, which affects the packets' electromagnetic fields and also allows one to develop new diagnostic tools for materials science, atomic and molecular physics, nuclear physics, and so forth

    Bicrossproduct Hopf quasigroups

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    We recall the notion of Hopf quasigroups introduced previously. We construct a bicrossproduct Hopf quasigroup kM\bicross k(G) from every group XX with a finite subgroup GXG\subset X and IP quasigroup transversal MXM\subset X subject to certain conditions. We identify the octonions quasigroup GOG_O as transversal in an order 128 group XX with subgroup Z23Z_2^3 and hence obtain a Hopf quasigroup kG_O\lcocross k(Z_2^3) as a particular case of our construction.Comment: 16 pages latex no figure
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