Multichannel parametrization of \pi N scattering amplitudes and extraction of resonance parameters

We present results of a new multichannel partial-wave analysis for \pi N scattering in the c.m. energy range 1080 to 2100 MeV. This work explicitly includes \eta N and K \Lambda channels and the single pion photoproduction channel. Resonance parameters were extracted by fitting partial-wave amplitudes from all considered channels using a multichannel parametrization that is consistent with S-matrix unitarity. The resonance parameters so obtained are compared to predictions of quark models

Partial-wave analysis of {\pi}-p {\to} {\eta}n and {\pi}-p {\to} K0{\Lambda} reactions

We investigate the hadronic reactions {\pi}N {\to} {\eta}N and {\pi}N {\to} K{\Lambda} via single-energy partial-wave analyses in the c.m. energy range 1080 to 2100 MeV. Our results for the K{\Lambda} channel are consistent with prior works; however, for the {\eta}N channel our results differ significantly from previous energy-dependent partial-wave analyses that violate the S-matrix unitarity. We present the first (new) results of {\eta}N and K{\Lambda} partial-wave amplitudes constrained by a unitary energy-dependent model. We obtain excellent predictions of integrated cross sections for the two reactions from a global energy-dependent solution. Our results imply that the region just above S11 (1535) has a major contribution from P11 (1710) for {\pi}-p {\to} {\eta}n, whereas the large peak near 1700 MeV in {\pi}-p {\to} K0{\Lambda} is dominated by contributions from both S11 (1650) and P11 (1710).Comment: 20 pages, 5 figure

Model Dependence of the Properties of S11 Baryon Resonances

The properties of baryon resonances are extracted from a complicated process of fitting sophisticated, empirical models to data. The reliability of this process comes from the quality of data and the robustness of the models employed. With the large of amount of data coming from recent experiments, this is an excellent time for a study of the model dependence of this extraction process. A test case is chosen where many theoretical details of the model are required, the S11 partial wave. The properties of the two lowest N* resonances in this partial wave are determined using various models of the resonant and non-resonant amplitudes.Comment: 24 pages, 10 figures; revised fits with error estimates, expanded comparison between CMB and K-matrix model

Effect of exotic S=+1 resonances on KL0pK^0_L p scattering data

We consider the effect of an exotic S=+1 $\Theta^+$ resonance on the scattering of neutral kaons off protons. Explicit results are presented for the $K^0_L p$ total cross sections.Comment: 2 pages, 3 figure