Production Properties of $Q$ Mesons in $K^{\pm }p\to K^{\pm }{\pi }^{+}{\pi }^{-}p$ at 13 GeV

The momentum transfer ($t^{\prime }$) dependence of the $J^P=1^{+}{K}^{*}\pi$ and $\rho K$ partial waves in the $K^{\pm }{\pi }^{+}{\pi }^{-}$ system is presented. The production of the $Q_1$ meson ($m\sim 1300$ MeV), which has a large $\rho K$ decay mode, obeys approximate $s$-channel helicity conservation. In contrast the production of the $Q_2$ meson ($m\sim 1400$ MeV), which decays predominantly to $K^{*}\pi$, satisfies approximate $t$-channel helicity conservation. Furthermore the $Q_1$ production distributions are virtually identical, whereas the ${Q_2}^{\pm }$ distributions exhibit a distinct cross-over for $\left|t^{\prime }\right|\sim 0.18$ Ge${\mathrm{V}}^2$.