A significant isospin-1 enhancement in the cross sections for $\overline{p}p$ $\left(\overline{p}n\right)\to K^{*}\mathrm{}\left(890\right)\mathrm{}\overline{K}\pi \pi$ (${\overline{K}}^{*}K\pi \pi$) is observed at a mass of 2360 ± 25 MeV with a width $\Gamma <60\mathrm{}$ MeV. This mass and width are consistent with the $U$ meson and an enhancement reported in a recent Brookhaven National Laboratory backward ${\pi }^{-}p$ missing-mass experiment. Whereas we agree with the Brookhaven National Laboratory $\overline{N}N$ total cross section measurements on the ${{\pi }_1}^{*}\mathrm{}\left(2350\right)\mathrm{}$ position, our width is clearly inconsistent with their value of 140 MeV.

• Received 13 April 1970

DOI:https://doi.org/10.1103/PhysRevLett.24.1257