Search for isotensor exotic meson and twist 4 contribution to ${\gamma }^{\ast }\gamma \to \rho \rho$

Abstract

We present a theoretical estimate for the cross-section of exclusive ${\rho }^{+}{\rho }^{-}$ and ${\rho }^0{\rho }^0$-meson production in two photon collisions when one of the initial photons is highly virtual. We focus on the discussion of the twist 4 contributions which are related to the production of an exotic isospin 2 resonance of two $\rho$ mesons. Our analysis shows that the recent experimental data obtained by the L3 Collaboration at LEP can be understood as a signal for the existence of an exotic isotensor resonance with a mass around $1.5\mathrm{GeV}$.

Comments: 8 pages, 5 figures