Observation of Two Strangeness-One Axial-Vector Mesons

We present a partial-wave analysis of the $K^{\pm }{\pi }^{+}{\pi }^{-}$ system in $K^{\pm }p\to K^{\pm }{\pi }^{+}{\pi }^{-}p$ at 13 GeV. Evidence is given for the existence of two $J^P=1^{+}$ mesons: one at ∼ 1300 MeV ($\Gamma \sim 200$ MeV) coupling principally to $\rho K$ and the other at ∼ 1400 MeV ($\Gamma \sim 160$ MeV) coupling principally to $K^{*}\pi$.