Multidimensional Resonance Analysis of $Λ_c^+ \to pK^-π^+$

Abstract

We present the results of a five-dimensional resonant amplitude analysis of the $Λ_c^+{\to}pK^{-}π^{+}$ system based on $946\pm 38$ reconstructed decays. These data were produced in 500 GeV/$c$ $π^-$-N interactions by Fermilab experiment E791. We report measurements of the amplitudes for $Λ_c^+$ decay into nonresonant $pK^-π^+$ and to $p\bar{K}^{*0}(890)$, $Δ^{++}(1232)K^-$, and $Λ(1520)π^+$ and we comment on other possible resonant enhancements. This is the first complete amplitude analysis of the $Λ_c^{+}{\to}pK^{-}π^{+}$ system. We find that $(54.8\pm5.5\pm3.5)$% of the decays are nonresonant, $(19.5\pm2.6\pm1.8)$% of the decays are via the $\bar{K}^{*0}$ resonance, $(18.0\pm2.9\pm2.9)$% of the decays are via the $Δ^{++}$ resonance, and $(7.7\pm1.8\pm1.1)$% of the decays are via the $Λ(1520)$ resonance. We find evidence for an increasingly negative polarization of the $Λ_c^+$ baryons as a function of $p_T^2$, in agreement with a recent model\cite{dha} and with a related measurement\cite{jez}.