Cross section of the reaction e+e- → π+π-π+π- below 1 GeV at CMD-2

Using 3.07 pb(-1) of data collected in the energy range 0.60-0.97 GeV by CMD-2, about 150 events of the process e(+)e(-) --> pi(+) pi(-) pi(+) pi(-) have been selected. The energy dependence of the cross section agrees with the assumption of the alpha(1)(1260)pi intermediate state which is dominant above 1 GeV. For the first time pi(+) pi(-) pi(+) pi(-) events are observed at the rho meson energy. Under the assumption that all these events come from the rho meson decay, the value of the cross section at the rho meson peak corresponds to the following decay width: Gamma(rho(0) --> pi(+) pi(-) pi(+) pi(-)) = (2.8 +/- 1.4 +/- 0.5) keV or to the branching ratio B(rho(0) --> pi(+) pi(-) pi(+) pi(-)) = (1.8 +/- 0.9 +/- 0.3) . 10(-5). (C) 2000 Published by Elsevier Science B.V. All rights reserved.