Spin-parity analysis of p¯p→E(1420)X

A Dalitz-plot analysis of 620 E(1420) events was performed on the reaction p¯p→($K_S^0$ $K^{+}$ ${\pi }^{\mathrm{-}}$)X at 6.6 GeV/c, obtained at the Brookhaven National Laboratory Multiparticle Spectrometer facility. The mass and width of the E(1420) peak are 1424±3 and 60±10 MeV, respectively. The best fit to the E(1420) is a $J^{\mathrm{PG}}$ ${=0\mathrm{}}^{\mathrm{-}+}$ state with a substantial δπ decay mode, produced over a large nonresonant background of $1^{++}$ $K^{\mathrm{*}}$K and phase space. This fit shows the same characteristics as the E(1420) observed in our companion ${\pi }^{\mathrm{-}}$p experiment.