The kaon photoproduction is investigated at the threshold energy. We discuss ͑i͒ the difference between the pseudoscalar ͑PS͒ and the pseudovector ͑PV͒ coupling descriptions on the KNY interaction, ͑ii͒ the contributions of t-channel poles of vector and axial vector mesons, and ͑iii͒ the contributions of nucleon and hyperon resonances to the E 0 ϩ amplitude. We suggest that total cross sections near threshold can be used to estimate the leading coupling constant, g KN⌳ and to make clear which description is the better of PS and PV coupling schemes for this reaction from future experiments. ͓S0556-2813͑96͒01010-2͔PACS number͑s͒: 25.20. Lj, 25.80.Nv, 13.75.Jz

g KN⌳ and g KN⌺ are calculated using a QCD sum rule motivated method used by Reinders, Rubinstein, and Yazaki to extract hadron couplings to Goldstone bosons. The SU͑3͒ symmetry breaking effects are taken into account by including the contributions from the strange quark mass and assuming different values for the strange and the up-down quark condensates. We find g KN⌳ /ͱ4ϭϪ1.96 and g KN⌺ /ͱ4ϭ0.33.

The accelerator mass spectrometry facility at the Seoul National University (SNU-AMS) was completed in December 1998 and a report was presented at the Vienna AMS conference in September 1999. At the conference, we described the basic components of our accelerator system and reported the results of the performance test. Since then, extensive testing of the accuracy and reproducibility of the system has been carried out, and about 200 unknown samples have been measured so far. We obtained a precision of 4‰ for modern samples, and an accuracy of approximately 40 yr was demonstrated by analyzing samples that were previously dated with a conventional technique and by other AMS laboratories. We present these results here, together with detailed descriptions of our data-taking and analysis procedures.

A SU (2) effective lagrangian is extended to a SUL(3) ⊗ SUR(3) by including the vector and axial vector meson. With this effective lagrangian, electromagnetic form factors of charged pion and kaon are calculated in both time and space like regions. The pseudoscalar meson loops are taken into account. Good agreement with experimental data is obtained for those form factors and charged pseudoscalar meson radii. Decay widths of ρ → ππ and φ → K + K − are also calculated and shown to agree with experimental data very well.

ABSTRACT. We present the current status of accelerator mass spectrometry (AMS) dating of iron artifacts at Seoul National University (SNU). In ancient iron production, charcoal was widely used as carbon for the smelting process, whereas coal is used in modern times. If reliable data could be obtained from carbon by using AMS, ancient iron artifacts could be traced to their production age. In normal acid treatment, it is not easy to extract carbon due to its colloidal property. The negative charge property of the carbon colloid, however, makes it possible for it to be precipitated with positive ions by dissolving the iron chemically. An extraction yield of the carbon incorporated in modern cast iron of about 70% is attained. More refined methods to increase the extraction rate are under progress for archaeological applications.