Reexamination of the role of the Δ* resonances in the pp → nK+Σ+ reaction.

In this work, the role of the Δ* resonances in the process of pp → nK+Σ+ are systematically investigated with the effective Lagrangian approach and the isobar model. We find that a P31 state, either Δ*(1750) or Δ*(1910) is favored by the data while the P33 state, namely Δ*(1920), has small contribution. Besides, either the subthreshold S31Δ*(1620) resonance or strong nΣ final state interaction or both have a possible contribution at near threshold region, depending on the measured cross sections. We demonstrate the invariant mass distributions and the Dalitz plots in order to investigate whether it is possible to distinguish the controversial KΣ production mechanism in these observables. [ABSTRACT FROM AUTHOR]