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 — preprints:2004:ttp04-26 [2016/03/15 20:39] (current) Line 1: Line 1: + ====== TTP04-26 The radiative return and form factors at large $Q^2$ ====== + + + The measurement of the pion form factor and, more + ​generally,​ of the cross section for electron--positron annihilation + into hadrons through the radiative return has become an important + task for high luminosity colliders such as the $\Phi$- or + ​$B$-meson factories. For a detailed understanding and analysis + of this reaction, the construction of a Monte Carlo program, + ​PHOKHARA,​ has been undertaken. A brief overview of + the most recent developments is presented, which include the combination + of initial- and final-state radiation in the case of two-pion + ​production. Baryon pair production is now included and + the pion form factor is extended into the region of large $Q^2$. + A model for the kaon + form factor is discussed which is + ​fitted to $K^+K^-$ and $K^0\bar{K}^0$ data and which + leads to predictions for the $\tau$-decay into $K^-K^0\nu$. + ​ + |**J.H. Kuhn** ​ | + |**      Proceedings of the Eighth International Workshop on Tau Lepton Physics (TAU 04) 14-17 September 2004, Nara, Japan **  | + | {{preprints:​2004:​ttp04-26.pdf|PDF}} {{preprints:​2004:​ttp04-26.ps|PostScript}} ​  | + | |