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arXiv · hep-ph/0203075

Four-pion production in e+ e- annihilation

G. Ecker·R. Unterdorfer
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Abstract

We calculate the processes e+ e- -> 4 pions and tau -> nu_tau + 4 pions to O(p^4) in the low-energy expansion of the standard model. The chiral amplitudes of O(p^4) can be extended via resonance exchange to energies around 1 GeV. Higher-order effects have been included in the form of omega, a_1 and double rho exchange and by performing a resummation of the pion form factor. The predicted cross sections and the branching ratios BR(rho -> 4 pions) are in good agreement with available data.

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G. Ecker, R. Unterdorfer. 2002-06-18. Four-pion production in e+ e- annihilation. https://doi.org/10.1007/s10052-002-0960-8

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