On the trail of QCD exotics

QCD predicts the existence of 'exotic' structures, prominent among them bei ng those with explicit gluonic degrees of freedom, such as q (q) over bar g hybrids and gg gluons. We report here the discovery of J(PC) = 1(+-) meson s which must be exotic (most likely q (q) over bar g) because q (q) over ba r mesons can not have these quantum numbers. One such meson with mass simil ar to 1370 MeV has been identified in its decay into eta pi(-), and a secon d with mass similar to 1600 MeV has been identified in both p pi(-) and eta 'pi(-) decay channels.