Spin-parity analysis of p¯p→E(1420)X

Abstract

A Dalitz-plot analysis of 620 E(1420) events was performed on the reaction p\ifmmode\bar\else\textasciimacron\fi{}p\ensuremath{\rightarrow}(${K}_{S}^{0}$${K}^{+}$${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$)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\ifmmode\pm\else\textpm\fi{}3 and 60\ifmmode\pm\else\textpm\fi{}10 MeV, respectively. The best fit to the E(1420) is a ${J}^{\mathrm{PG}}$${=0}^{\mathrm{\ensuremath{-}}+}$ state with a substantial \ensuremath{\delta}\ensuremath{\pi} 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 ${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$p experiment.