Exploring light-cone sum rules for pion and kaon form factors

  • J. Bijnens
  • A. Khodjamirian
Theoretical Physics

Abstract.

We analyze the higher-twist effects and the SU(3)-flavor symmetry breaking in the correlation functions used to calculate form factors of pseudoscalar mesons in the QCD light-cone sum rule approach. It is shown that the Ward identities for these correlation functions yield relations between twist-4 two- and three-particle distribution amplitudes. In addition to the relations already obtained from the QCD equations of motions, we have found a new one. With the help of these relations, the twist-4 contribution to the light-cone sum rule for the pion electromagnetic form factor is reduced to a very simple form. Simultaneously, we correct a sign error in an earlier calculation. The updated light-cone sum rule prediction for the pion form factor at intermediate momentum transfers is compared with the recent Jefferson Lab data. Furthermore, from the correlation functions with strange-quark currents the kaon electromagnetic form factor and the \(K\to \pi\) weak transition form factors are predicted with \(O(m_s)\char126O(m_K^2)\) accuracy.

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Copyright information

© Springer-Verlag Berlin Heidelberg / Società Italiana di Fisica 2002

Authors and Affiliations

  • J. Bijnens
    • 1
  • A. Khodjamirian
    • 2
  1. 1.Department of Theoretical Physics, Lund University, Sölvegatan 14A, 223 62 Lund, Sweden SE
  2. 2. Institut für Theoretische Teilchenphysik, Universität Karlsruhe, 76128 Karlsruhe, Germany DE

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