Impact of vector mesons polarization on its interaction with matter

Abstract

The production of unstable particles on different nuclei provides the possibility to determine the total cross section of the interaction of vector mesons $V=\rho,\omega,\varphi, K^{*0}(892),J/\psi$ etc. with nucleons. This interaction is defined by a set of amplitudes that correspond to the transverse (helicity $\lambda=\pm 1$) or longitudinal ($\lambda=0$) polarization of the vector meson. The total cross section for the interaction of transversely polarized vector mesons with nucleon $\sigma_T=\sigma(V_T N)$ has been extracted from the coherent photoproduction of vector mesons off nuclei, while the vector meson production in charge exchange reactions as $\pi^\pm(K^\pm)+A\to V^0(K^{*0})+A'$ provides the unique opportunity to obtain the not yet measured total cross section for longitudinally polarized vector meson interacting with nucleon $\sigma_L=\sigma(V_L N)$. We shortly discuss the importance of the knowledge of $\sigma_L$ and possibility to extract its value from experiments on nuclear target.