Takamatsu, K (reprint author), Inst High Energy Phys, Beijing 100049, Peoples R China.
Based on 58 million BESII J/psi events, the (K) over bar*(892)(0)K(+)pi(-) channel in K(+)K(-)pi(+)pi(-) is studied. A clear low mass enhancement in the invariant mass spectrum of K(+)pi(-) is observed. The low mass enhancement does not come from background of other J/psi decay channels, nor from phase space. Two independent partial wave analyses have been performed. Both analyses favor that the low mass enhancement is the K, an iso-spinor scalar resonant state. The average mass and width of the K in the two analyses are 878 +/- 23(-55)(+64) MeV/c(2) and 499 +/- 52(-87)(+55) MeV/c(2), respectively, corresponding to a pole at (841 +/- 30(-73)(+81)) -i(309 +/- 45(-72)(+48)) MeV/c(2). (c) 2006 Elsevier B.V. All rights reserved.