Poles of the Zagreb analysis partial-waveTmatrices

Abstract

The Zagreb analysis partial-wave T matrices included in the Review of Particle Physics [by the Particle Data Group (PDG)] contain Breit-Wigner parameters only. As the advantages of pole over Breit-Wigner parameters in quantifying scattering matrix resonant states are becoming indisputable, we supplement the original solution with the pole parameters. Because of an already reported numeric error in the S 11 analytic continuation [Batinić et al., Phys. Rev. C 57, 1004(E) (1997); arXiv:nucl-th/9703023], we declare the old BATINIC 95 solution, presently included by the PDG, invalid. Instead, we offer two new solutions: (A) corrected BATINIC 95 and (B) a new solution with an improved S 11 π N elastic input. We endorse solution (B).

Coupled-channel dynamics in the reactions πN → πN, ηN, KΛ, KΣ

“…greb analysis actually two poles are found in the complex plane in the region Re z ∼ 1.7 GeV [150,154]. This scenario is similar to the present fit A that also has a second state, though far in the complex plane, called N (1750) 1/2 + (cf.…”

Regge phenomenology of theN*andΔ*poles

“…Other pole extractions are available in the literature. These include, the speed plot extraction from πN → πN amplitudes by Höhler [45]; the SAID pole parameters given in [35] obtained from the SAID-GW WI08 partial wave analysis of πN elastic scattering [41]; the Kent State University (KSU) pole extraction in [46] using a multichannel parametrization of πN scattering amplitudes; the Pittsburgh-Argonne National Lab (P-ANL) pole extraction in [47]; the Giessen group coupled-channel analysis of η production and photoproduction data on the proton [48]; the Argonne National Lab-Osaka (ANL-O) amplitude analysis of πN → πN , ηN , KΛ, KΣ and γN → πN , ηN ,KΛ, KΣ data [49]; and the Zagreb analysis in [50] based on the CMB coupled-channel approach; Höhler, SAID, KSU, P-ANL, Giessen and ANL-O do not provide uncertainties in their pole extractions and the Zagreb group analysis only studies the N * spectrum, hence, we choose not to include them in our work. Also, we do not include superseded pole extractions within the same reaction models.…”

Eta photoproduction in a combined analysis of pion- and photon-induced reactions

“…[34][35][36][37][38]. Considering a broader energy range up to and beyond 2 GeV, K-matrix [7,[39][40][41][42][43][44] and unitary isobar [45] models are practical tools to perform an analysis of large amounts of data. Sometimes, the real part of the self-energies is neglected and only on-shell intermediate states are maintained, which reduces the complexity of the calculations.…”