Proposed Search for $a_0^0(980)-f_0(980)$ Mixing in Polarization Phenomena

Abstract

The $K^{+}$ and $K^0$ meson mass difference induces the mixing of the $a_0^0(980)$ and $f_0(980)$ resonances, the amplitude of which, between the $K^{+}{K}^{-}$ and $K^0{\bar{K}}^0$ thresholds, is large in magnitude, of the order of $m_K\sqrt{m_{K^0}^2-m_{K^{+}}^2}\approx \sqrt{\alpha }{m}_K^2$, and possesses the phase sharply varying by about 90${}^{\circ }$. We suggest performing the polarized target experiments on the reaction ${\pi }^{-}p\to \eta {\pi }^{0}n$ at high energy in which the fact of the existence of $a_0^0(980)-f_0(980)$ mixing can be unambiguously and very easily established through the presence of a strong jump in the azimuthal asymmetry of the $\eta {\pi }^0$ $S$ wave production cross section near the $K\bar{K}$ thresholds. The presented estimates of the polarization effect to be expected in experiment are to a great extent model independent.

Comments: RevTeX, 9 pages, 1 figure. A number of typographical and grammatical errors corrected