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 — preprints:2002:ttp02-08 [2016/03/17 11:03] (current) Line 1: Line 1: + ====== TTP02-08 Exploring Light-Cone Sum Rules for Pion and Kaon Form Factors ====== + + + We analyze the higher-twist effects and the $SU(3)$-flavour 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 the 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 + $O(m_s)\sim O(m_K^2)$ accuracy. + + |**Johan Bijnens and Alexander Khodjamirian**  | + |**  Eur.Phys.J.C  26 67-79 2002  **  | + | {{preprints:2002:ttp02-08.pdf|PDF}} {{preprints:2002:ttp02-08.ps|PostScript}} [[http://arxiv.org/abs/hep-ph/0206252|arXiv]]   | + | |