27 research outputs found

    A Perturbative Calculation of the Electromagnetic Form Factors of the Deuteron

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    Making use of the effective field theory expansion recently developed by the authors, we compute the electromagnetic form factors of the deuteron analytically to next-to-leading order (NLO). The computation is rather simple, and involves calculating several Feynman diagrams, using dimensional regularization. The results agree well with data and indicate that the expansion is converging. They do not suffer from any ambiguities arising from off-shell versus on-shell amplitudes.Comment: 22 pages, 8 figures. Discussion of effective range theory added, typos correcte

    Chiral π\pi-exchange NN-potentials: Results for diagrams proportional to g_A^4 and g_A^6

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    We calculate in (two-loop) chiral perturbation theory the local NN-potentials generated by the three-pion exchange diagrams proportional to g_A^4 and g_A^6. Surprisingly, we find that the total isoscalar central 3π3\pi-exchange potential vanishes identically. The individually largest 3π3\pi-exchange potentials are of isoscalar spin-spin, isovector central and isoscalar tensor type. For these potentials simple analytical expressions can be given. The strength of these dominant 3π3\pi-exchange potentials at r=1.0 fm is 4.6 MeV, 2.9 MeV and 1.4 MeV, respectively. Furthermore, we observe that the spin-spin and tensor potentials due to the diagrams proportional to g_A^6 do not exist in the infinite nucleon mass limit.Comment: 8 pages, 5 figure

    Description of inclusive scattering of 4.045 GeV electrons from D

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    We exploit a relationship between the Structure Functions of nucleons, the physical deuteron and of a deuteron, composed of point-nucleons to compute angular distributions of inclusive cross sections of 4.05 GeV electrons. We report general agreement with data and interpret the remaining discrepancies. We discuss the potential of the data for information on neutron structure functions Fkn(x,Q2)F_k^n(x,Q^2) and the static form factor GMn(Q2)G_M^n(Q^2).Comment: 9 pages,1 Fig., PS fil

    g_{\pi \Lambda \Sigma} and g_{K \Sigma \Xi} from QCD sum rules

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    The coupling constants g_{\pi \Lambda \Sigma} and g_{K \Sigma \Xi} are calculated in the QCD sum rule approach using the three-point function method and taking into account the SU(3) symmetry breaking effects. The pattern of SU(3) breaking appears to be different from that based on SU(3) relations.Comment: revtex, 9 page

    GRS computation of deep inelastic electron scattering on 4He

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    We compute cross sections for inclusive scattering of high energy electrons on 4He, based on the two lowest orders of the Gersch-Rodriguez-Smith (GRS) series. The required one- and two-particle density matrices are obtained from non-relativistic 4He wave functions using realistic models for the nucleon-nucleon and three-nucleon interaction. Predictions for E=3.6 GeV agree well with the NE3 SLAC-Virginia data.Comment: 18 pages, 7 figures, submitted to PR

    Experimental progress in positronium laser physics

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