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The $Delta(1232)$ axial charge and form factors from lattice QCD

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 نشر من قبل Constantia Alexandrou
 تاريخ النشر 2011
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 تأليف C. Alexandrou




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We present the first calculation on the $Delta$ axial-vector and pseudoscalar form factors using lattice QCD. Two Goldberger-Treiman relations are derived and examined. A combined chiral fit is performed to the nucleon axial charge, N to $Delta$ axial transition coupling constant and $Delta$ axial charge.



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We present a lattice QCD calculation of the $Delta(1232)$ matrix elements of the axial-vector and pseudoscalar currents. The decomposition of these matrix elements into the appropriate Lorentz invariant form factors is carried out and the techniques to calculate the form factors are developed and tested using quenched configurations. Results are obtained for 2+1 domain wall fermions and within a hybrid scheme with domain wall valence and staggered sea quarks. Two Goldberger-Treiman type relations connecting the axial to the pseudoscalar effective couplings are derived. These and further relations based on the pion-pole dominance hypothesis are examined using the lattice QCD results, finding support for their validity. Utilizing lattice QCD results on the axial charges of the nucleon and the $Delta$, as well as the nucleon-to-$Delta$ transition coupling constant, we perform a combined chiral fit to all three quantities and study their pion mass dependence as the chiral limit is approached.
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