Speaker
Description
Light vector mesons $V=\rho,\omega,\varphi, K^*$ etc. can be transversely (helicity $\lambda=\pm 1$) or longitudinally ($\lambda=0$ ) polarized.\
Has their polarization impact on their interaction with nucleons and nuclei?\
The unstable meson total cross section with nucleon can be extracted by measuring the absorption of mesons in the production off nuclei as
the nuclear absorption depends on the meson-nucleon total cross section and consequently on the vector meson polarization.\
Whereas the meson coherent photoproduction off nuclei allows to determine the transverse total cross section $\sigma_T(VN)$ the incoherent production can be a good tool
to extract the information on the value of the total cross section of longitudinally polarized vector meson with nucleon $\sigma_L(VN)$. In the talk we discuss the importance of a knowledge
of this cross sections and possibility to determine these quantities from $\omega$ mesons photoproduction at JLAB and charge exchange reaction on a set of nuclei $\pi^-A\to VA'$ using the
COMPASS++/AMBER facility at SPS,CERN.
