Eur. Phys. J. C 24, 535-545 (2002)
DOI: 10.1007/s10052-002-0960-8
Four-pion production in e+e- annihilation
G. Ecker and R. UnterdorferInstitut für Theoretische Physik, Universität Wien, Boltzmanngasse 5, 1090 Vienna, Austria
(Received: 8 March 2002 / Published online: 14 June 2002 )
Abstract
We calculate the processes
and
to
O(p4) in the low-energy expansion of the standard
model. The chiral amplitudes of
O(p4) can be extended via
resonance exchange to energies around 1 GeV. Higher-order effects
have been included in the form of
,
a1 and double
exchange and by performing a resummation of the pion form
factor. The predicted cross sections and the branching ratios
are in good agreement with
the
available data.
© Società Italiana di Fisica, Springer-Verlag 2002