Study of the $\eta \pi$ and ${\eta }^{\prime }\pi$ spectra and interpetation of possible exotic $J^{PC}=1^{-+}$ mesons

Abstract

We discuss a coupled channel analysis of the $\eta \pi$ and ${\eta }^{\prime }\pi$ systems produced in ${\pi }^{-}p$ interactions at 18 GeV/$c$. We show that known $Q\bar{Q}$ resonances, together with residual soft meson-meson rescattering, saturate the spectra including the exotic $J^{PC}=1^{-+}$ channel. A possibility of a narrow exotic resonance at a mass near 1.6 GeV/$c^2$ cannot, however, be ruled out.

4 pages, 2 figures