Energy dependence of barKN interactions and resonance pole of strange dibaryons

TL;DR

This paper investigates the resonance energies of strange dibaryons using two models of barKN interactions, revealing different predictions for resonance poles and emphasizing the importance of binding energy studies for understanding the Lambda(1405) region.

Contribution

It compares energy-independent and energy-dependent potential models for barKN interactions, showing they predict different resonance structures of strange dibaryons.

Findings

Energy-independent model predicts one resonance pole.

Energy-dependent model predicts two resonance poles.

Both models fit available data equally well.

Abstract

We study the resonance energy of the strange dibaryons using two models with the energy-independent and energy-dependent potentials for the s-wave barKN interaction, both of which are derived by certain reductions from the leading order term of the effective chiral Lagrangian. These potential models produce rather different off-shell behaviors of the two-body barKN - piSigma amplitudes in I=0 channel, i.e., the model with energy-independent (energy-dependent) potential predicts one (two) resonance pole in the Lambda(1405) region, while they describe the available data equally well. We find that the energy-independent potential model predicts one resonance pole of the strange dibaryons, whereas the energy-dependent potential model predicts two resonance poles: one is the shallow quasi-bound state of the barKNN, and another is the resonance of the piYN with large width. An investigation of the binding energy of the strange dibaryons will make a significant contribution to clarify resonance structure of s-wave barKN - piSigma around the Lambda(1405) region.