Narrow Results

The present status of kaon photo- and electroproduction on the nucleon is briefly reviewed. Some current important issues in this field are discussed.

Recent progress on the precision laser spectroscopy of antiprotonic helium atoms, as well as on the x-ray spectroscopy of kaonic helium atoms are presented. These two may appear to be unrelated topics (except for the fact that both being exotic helium atoms), but in fact a past study of kaonic helium system led to the serendipitous discovery of antiprotonic helium. Some historical background connecting these two exotic helium atoms, as well as future prospects are discussed.

We have phenomenologically investigated the kaon photoproduction process γp → K⁺Λ by combining different types of hadronic form factors (HFFs) inside a covariant isobar model. We obtained the best model with the smallest χ²/N by using the dipole form factor in the Born terms and a combination of the dipole, Gaussian, as well as generalized dipole form factors in the hadronic vertices of the nucleon, kaon and hyperon resonances. By utilizing this model we found that the experimental data used in the analysis are internally consistent, whereas the behavior of differential cross-section at forward angles is not significantly affected by the variation of hadronic coupling constants (CCs) and form factor cutoffs in the model.