13 research outputs found

    Instanton-induced charm contribution to polarized deep-inelastic scattering

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    Recent data on B decays involving η′\eta' may be explained if the singlet axial current of charmed quarks has large matrix element to η′\eta', and instantons were shown to be able to generate this effect. We study the magnitude of charm contributions to nucleon polarized structure functions generated in a similar way. Comparing the charm contribution, which is related to a dim(6) gluonic operator, to that of light quarks, which are related by the anomaly equation to GG~G\tilde G, we found that Δc/ΔΣ\Delta c/\Delta\Sigma = -(0.2-0.08). Future experiments like COMPASS at CERN identifying charm production in DIS can measure this ``intrinsic polarized charm'' component of the nucleon.Comment: 12 pages, LaTeX, RevTex, epsfig.sty, 3 figures, one sign in Euclidean definitions correcte

    The Constituent Quark Limit and the Skyrmion Limit of the Chiral Quark Soliton Model

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    We calculate gA3g_A^3 and gA0g_A^0 in the Chiral Quark-Soliton Model (or equivalently in semibosonized Nambu--Jona-Lasinio model) in the limit of small and large soliton size. In small soliton limit we recover the results of the Constituent Quark Model. The agreement between the two models is achieved due to the recently calculated 1/\Nc contributions to gA3g_A^3 and to gA0g_A^0. In the case of gA3g_A^3 these terms arise from the {\it time-ordering} of the collective operators. For large solitons simple scaling arguments show that the 1/\Nc contributions vanish with the inverse power of the soliton size.Comment: One additional reference, 14 pages, latex, revtex, picte

    Electromagnetic Form Factors of the SU(3) Octet Baryons in the semibosonized SU(3) Nambu-Jona-Lasinio Model

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    The electromagnetic form factors of the SU(3) octet baryons are investigated in the semibosonized SU(3) Nambu--Jona-Lasinio model (chiral quark-soliton model). The rotational 1/Nc1/N_c and strange quark mass corrections in linear order are taken into account. The electromagnetic charge radii of the nucleon and magnetic moments are also evaluated. It turns out that the model is in a remarkable good agreement with the experimental data.Comment: RevTex is used. 37 pages. The final version to appear in Phys. Rev. D. 13 figures are include

    A Top Quark Soliton and its Anomalous Chromomagnetic Moment

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    We show that under the assumption of dynamical symmetry breaking of electro weak interactions by a top quark condensate, motivated by the Top Mode Standard Model, the top quark in this effective theory can be considered then as chiral color soliton (qualiton). This is realized in an effective four-fermion interaction with chiral SU(3)cSU(3)_c as well as SU(2)L⊗UY(1)SU(2)_L\otimes U_Y(1) symmetry. In the pure top sector the qualiton consists of a top valence quark and a Dirac sea of top and anti-top quark coupled to a color octet of Goldstone pions. The mass spectra, isoscalar quadratic radii and the anomalous chromomagnetic moment due to a non-trivial color form factor are calculated with zero and finite current top masses and effects at the Hadron Colliders are discussed. The anomalous chromomagnetic moment turns out to have a value consistent with the top production rates of the D0- and CDF-measurements.Comment: LaTeX, using RevTeX.sty and aps.sty, without figures, 16 pages, to be published in Physical Review D. Full postscript version and figures available on request or via ftp://hadron.tp2.ruhr-uni-bochum.de/preprint.tp2/1995/08-95.tar.g
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