Neutral kaon photoproduction on the deuteron

Neutral kaon photoproduction on the deuteron has been investigated by including the final state effects and compared with the experimental data. Comparison shows that the models used in this calculation can reproduce the data in the $\Sigma$ channel regions fairly well but still give over predictions in the $\Lambda$ channel. It seems that the tensor target asymmetries are more suitable for studying the final state effects. The extractions of the elementary photoproduction amplitude are also demonstrated.Comment: 6 pages, 6 figures, talk given by A. Salam at Fourth Asia-Pacific Conference on Few-Body Problems in Physics 2008 (APFB08), Depok, Indonesia, August 19-23, 200

Missing Resonances in Kaon Photoproduction on the Nucleon

New kaon photoproduction data on a proton, gamma + p --> K+ + Lambda, are analyzed using a multipole approach. The background terms are given in terms of gauge invariant, crossing symmetric, Born diagrams with hadronic form factors, while the resonances are parameterized using Breit-Wigner forms. Preliminary results suggest a number of new resonances, as predicted by many quark model studies. A comparison between the extracted multipoles and those obtained from KAON-MAID is presented.Comment: 10 pages, 6 figures, invited talk at the International Symposium on Electrophotoproduction of Strangeness on Nucleons and Nuclei (SENDAI 03), Sendai, Japan, 16-18 Jun 200

Low Densities Instability of Relativistic Mean Field Models

The effects of the symmetry energy softening of the relativistic mean field (RMF) models on the properties of matter with neutrino trapping are investigated. It is found that the effects are less significant than those in the case without neutrino trapping. The weak dependence of the equation of state on the symmetry energy is shown as the main reason of this finding. Using different RMF models the dynamical instabilities of uniform matters, with and without neutrino trapping, have been also studied. The interplay between the dominant contribution of the variation of matter composition and the role of effective masses of mesons and nucleons leads to higher critical densities for matter with neutrino trapping. Furthermore, the predicted critical density is insensitive to the number of trapped neutrinos as well as to the RMF model used in the investigation. It is also found that additional nonlinear terms in the Horowitz-Piekarewicz and Furnstahl-Serot-Tang models prevent another kind of instability, which occurs at relatively high densities. The reason is that the effective sigma meson mass in their models increases as a function of the matter density.Comment: 25 pages, 10 figures, submitted to Phys. Rev.

Role of the K1K_1 meson in K0K^0 photoproduction off the deuteron

Neutral kaon photoproduction off the nucleon and deuteron has been reinvestigated by utilizing the new experimental data on both targets. An isobar model for elementary operator and impulse approximation for the reaction on the deuteron have been used. The available free parameters in the elementary model have been extracted from both elementary and deuteron data. In contrast to the elementary reaction, fitting the deuteron data requires an inclusion of weighting factor. The result indicates that the angular distribution of the elementary $K^0\Lambda$ process does not show backward peaking behavior.Comment: 4 pages, 4 figures, prepared for the Fifth Asia-Pacific Conference on Few-Body Problems in Physics 2011 (APFB2011), Seoul, Korea, August 22-26, 201