Σ photoproduction in the resonance region

Abstract

A study of γp → KΣ processes in an isobar model at tree level is reported. By comparing model calculations to the published SAPHIR data, we explore the possible role of different isospin I = 1 2 (N * ) and I = 3 2 (∆ * ) resonances in the reaction dynamics. In our analysis, the inclusion of the "missing" D13(1895) resonance does only slightly improve the global description of the Σ photoproduction data. More convincing signals for the presence of such a "missing" resonance emerged in the analysis of the isospin related γp → K + Λ reaction. Various implementations of the nonresonant part of the Σ photoproduction amplitude are presented. The sensitivity of the computed observables and extracted resonance parameters to the uncertainties inherent to the treatment of the non-resonant (background) diagrams are discussed.

Photoproduction of Θ baryon from the neutron

“…However, the necessity of the form factor seems obvious from physics point of view as it should reflect the size (or internal structure) of hadrons. For instance, the Born terms in the K + Λ photoproduction [22] produces too large total cross sections as shown in Fig. 2.…”

Scaling and resonances in elementaryK+Λphotoproduction

“…So-called hadrodynamic models based on effective Lagrangians have, for many years, been employed with moderate success to describe a wide range of hadronic and electromagnetic reactions, including the particular reaction that is the focus of this paper [17][18][19][20][21][22][23][24][25][26][27][28].…”

Strangeness production on the nucleon

“…Recent isobar models identified the three nucleon resonances S 11 (1650), P 11 (1710) and P 13 (1720) as leading N * contributions to the p(γ, K + )Λ reaction [25,27,29,31].…”

“…One had to wait until 1998, when the SAPHIR collaboration at Bonn [23,24] released the first extensive and accurate database for all three γp → K + Λ, K + Σ 0 and K 0 Σ + reactions. The results of this experiment clearly triggered renewed interest at various theoretical groups [25][26][27][28][29][30][31][32].…”