====== TTP02-08 Exploring Light-Cone Sum Rules for Pion and Kaon Form Factors ======
 
 
   <hidden 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.
 </hidden>
|**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]]   |
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