Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9851450 | Nuclear Physics A | 2005 | 14 Pages |
Abstract
The γpâK+Ï0Î and γpâK+ÏΣ reactions are studied in the kinematic region where the Ï0Î(1116) and ÏΣ(1192) pairs originate dominantly from the decay of the Σ(1385) and Î(1405) resonances. We consider laboratory photon energies around 2 GeV, significantly above the threshold for producing the K+Σ(1385) and K+Î(1405) final states. We compute for both reactions the process in which the ingoing photon dissociates into a real K+ and a virtual Kâ, the off-shell Kâ scattering subsequently off the proton target to produce the Ï0Î or ÏΣ pair. The KâpâÏ0Î and KâpâÏΣ amplitudes are calculated in the framework of a chiral coupled-channel effective field theory of meson-baryon scattering. The structure of the amplitudes reflects the dominance of the Î(1405) in the ÏΣ channel and of the Σ(1385) in the ÏÎ channel. The full pion-hyperon final state interaction is included in these amplitudes. We extract from the calculated cross section the gauge-invariant double kaon pole term. We find this term to be large and leading to sizeable cross sections for both the γpâK+Ï0Î and γpâK+ÏΣ reactions, in qualitative agreement with the scarce data presently available. Accurate measurements of these cross sections should make it possible to extract the contribution of the double kaon pole and hence to assess the possibility of studying kaon-nucleon dynamics just below threshold through these reactions.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Nuclear and High Energy Physics
Authors
Matthias F.M. Lutz, Madeleine Soyeur,