Phenomenological studies of CLAS data on double charge pion electroproduction

Comprehensive studies of unpolarized $\pi^{-} \pi^{+} p$ electroproduction cross-sections, for the first time available from CLAS [1,2], were carried out within the framework of phenomenological approach [3]. Analysis of these data allowed us to establish all important mechanisms, contributing to this exclusive channel in $N^{*}$ excitation region at photon virtualities from 0.2 to 1.5 GeV$^2$. Electrocouplings for $P_{11}(1440)$, $D_{13}(1520)$ states at $Q^{2}$ $<$ 0.6$GeV^2$ were obtained from the analysis of CLAS data [1]. The contributions from various mechanisms in terms of both amplitudes and single differential cross-sections were determined from the data fit. This information is of particular interest for $N^{*}$ studies in coupled channel approaches under development at EBAC [4]. \newline $[1]$ G.V.Fedotov, et. al., Bull. of Russian Academy of Science,71,328 (2007). \newline [2] M.Ripani, et. al., Phys. Rev.,91,0222002 (2003). \newline [3] V.I.Mokeev, et. al., Int. Workshop on the Physics of Excited Baryons (NSTAR05) Tallahassee, Florida, 10-15 Oct 2005, ed by V.Crede, P.Eugenio and S.Capstick, p.47. \newline [4] A.Matsuyama, et.al., Phys.Rep.,439,193 (2007); B.Julia-Diaz, et.al., arXiv:0704.1615.