Photoproduction of K+Λ0 on polarized protons

Polarization Observables in γp → K+ + Λ and K+ + Σ0 Using Circularly Polarized Photons on a Polarized Frozen Spin Target

“…A similar expression can be obtained for the F asymmetry. The red diamond data is CLAS g9b data, green triangles are GRAAL data (2009) [9], and the black circles are Bonn data (1978) [10]. The blue solid curve is the Kaon-MAID model [7], the red dotted curve is the RPR-Ghent model [11], and the magenta dashed curve is the Bonn-Gatchina model [8].…”

Strangeness production on the nucleon

“…With the aid of the Legendre function of the 2 nd kind, defined as: 20) and the interchange of the integration variables, one eventually arrives at the FroissartGribov projection:…”

“…The earliest works clearly lacked the presence of a reliable database. In those days, pioneering kaon photoproduction experiments were performed at Bonn, Tokyo, Cornell and CalTech [17][18][19][20][21][22] but the experimental facilities did only cover a limited energy range above the kaon production threshold. To make matters even worse, the accuracy of the measurements suffered from the very low counting rates, reflecting cross sections of the order of microbarns, compared to for example π photoproduction which are characterized by cross sections in the milibarn range.…”

Electroproduction of Strangeness

“…There are a few measurements (Fig. 4) (4) where (+) or ( -) refer to a A polarized parallel or antiparallel, respectively, to the y-axis denned by y = p 7 X px• A few data on the polarized target asymmetry T (as denned in Eq. (4), where ± refers to the proton rather than the A) also exist, 4 but the error bars are large, as for P. Both models predict the correct sign for T but, as noted by Workman, 22 a number of earlier models predict large polarizations with the wrong sign.…”

“…The data include differential cross sections, 1 total cross sections, 2 A-polarization measurements, and some measurements with a polarized target. 4 Much of the data is collected in the review by Genzel et al 5 A variety of theoretical techniques have been applied to the analysis of the photoproduction data in the medium energy region (below 2 GeV). These in clude dispersion relations, 6 multipole amplitude analyses, 7 and Feynman diagram techniques.…”