Résumé du preprint DAPNIA-06-469

DAPNIA-06-469
Polarization effects in the reaction
C. Adamuv sv c'in G. I. Gakh E. Tomasi-Gustafsson
The electron positron annihilation reaction into four pion production has been studied, through the channel  $e^++e^-\\rightarrow \\bar \\rho+\\rho $. The differential (and total) cross sections and various polarization observables for this reaction have been calculated in terms of the 
electromagnetic form factors of the corresponding $\\gamma^*\\rho\\rho $ current. 
The elements of the spin--density matrix of the $\\rho -$meson were also calculated. 
Numerical estimations have been done, with the help of 
phenomenological form factors obtained in the space--like region of the momentum transfer squared and analytically extended to the time-like region.

 

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