S. Y. Ryu

Search for

A search forKpp bound state (the lightest kaonic nucleus) has been performe d using theγd → KπX reaction at Eγ=1.5-2.4 GeV at LEPS / Pring-8. The di fferential cross section of Kπ photo-production o ff deuterium has been measured for the first time in this energy region, and a bump st ructure was searched for in the inclusive missing mass spectrum. A statistically significant bump structure was no t observed in the region from 2.22 to 2.36 GeV /c2, and the upper limits of the di fferential cross section for the Kpp bound state production were determined to be 0.1 − 7μ b (95% confidence level) for a set of assumed binding energy and width values.

K^-pp

Differential cross sections at

bound state via

t=t_{\text{min}}

\gamma d \rightarrow K^+ \pi^-X

and decay asymmetries for the

reaction at

\gamma p\rightarrow\phi p

E_\gamma=1.5-2.4

reaction have been measured using linearly polarized photons in the range 1.5 to 2.9 GeV. These cross sections were used to determine the Pomeron strength factor. The cross sections and decay asymmetries are consistently described by the

GeV

t

φ photoproduction on the proton at Eγ=1.5-2.9 GeV

-channel Pomeron and pseudoscalar exchange model in the

Photoproduction of

E_{\gamma}

\Lambda

region above 2.37 GeV. In the lower energy region, an excess over the model prediction is observed in the energy dependence of the differential cross sections at