Exclusive two ${\rho }^0$-mesons production in $\gamma {\gamma }^{\ast }$ collision

Abstract

We give a theoretical description of the L3 Collaboration data on the cross-section of the exclusive two $\rho$-mesons production in $\gamma {\gamma }^{\ast }$ collision with large photon virtuality. These data prove the scaling behaviour of the leading twist generalized distribution amplitude of vector mesons. They thus prove the relevance of a partonic description of the exclusive process $\gamma {\gamma }^{\ast }\to {\rho }^0{\rho }^0$ at $Q^2\ge 1.2\mathrm{Ge}{\mathrm{V}}^2$ and $W\le 3.0\mathrm{GeV}.$

6 pages, 1 eps figure