Perspectives of scalar- and vector-meson production in hadron-nucleus reactions

Abstract

The production and decay of vector mesons ($ρ, ω$) in $pA$ reactions at COSY energies is studied with particular emphasis on their in-medium spectral functions. It is explored within transport calculations, if hadronic in-medium decays like $π^+π^-$ or $π^0 γ$ might provide complementary information to their dilepton ($e^+e^-$) decays. Whereas the $π^+ π^-$ signal from the $ρ$-meson is found to be strongly distorted by pion rescattering, the $ω$-meson Dalitz decay to $π^0 γ$ appears promising even for more heavy nuclei. The perspectives of scalar meson ($f_0, a_0$) production in $pp$ reactions are investigated within a boson-exchange model indicating that the $f_0$-meson might hardly be detected in these collisions in the $K \bar{K}$ or $ππ$ decay channels whereas the exclusive channel $pp \to d a_0^+$ looks very promising.