[en] A series of experiments have been carried out by using a linearly polarized photon beam at the SPring-8/LEPS facility from December 2000 to June 2001. The photon beam asymmetries and differential cross sections of the p(γ-bar,K⁺)Λ and p(γ-barγ, K⁺)Σ⁰ reactions have been measured in the photon energy range from 1.5 GeV to 2.4 GeV at forward angles, 0 deg. < Θ_cm^K+ < 60 deg. . We report preliminary results of the photon beam asymmetries

[en] A series of experiments have been carried out by using linearly polarized photons at the SPring-8/LEPS facility from December 2000 to June 2001. The photon beam asymmetries of the p(γ vector, Κ⁺)Λ and p(γ vector, Κ⁺)Σ⁰ reactions have been obtained in the photon energy range from 1.5 GeV to 2.4 GeV at forward angles, 0deg < Θcm^Κ+ < 60deg. We report the experimental results. The experimental data will extend our knowledge of the Κ⁺ photoproduction mechanism including the effect of nucleon resonances. (author)

[en] The measurement of the p(γ vector, K⁺)Λ and p(γ vector, K⁺)Σ⁰ reactions was carried out at the SPring-8/LEPS facility from 2000 December to 2001 June. The photon beam asymmetry and the differential cross section were measured by a linearly polarized photon beam on proton. The nucleon resonances and the t-channel meson exchange will be investigated by this measurement. The experiment and the current status of analyses are discussed in this paper. (author)

[en] Here, we measure the inclusive production cross sections of hyperons and charmed baryons from e ⁺e ^- annihilation using a 800 fb ^-1 data sample taken near the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e ⁺e ^- collider. The feed-down contributions from heavy particles are subtracted using our data, and the direct production cross sections are presented for the first time. The production cross sections divided by the number of spin states for S = -1 hyperons follow an exponential function with a single slope parameter except for the Σ(1385) ⁺ resonance. Suppression for Σ(1385) ⁺ and Ξ(1530) ⁰ hyperons is observed. Among the production cross sections of charmed baryons, a factor of 3 difference for Λ$\genfrac{}{}{0ex}{}{+}{c}$ states over Σ _c states is observed. This observation suggests a diquark structure for these baryons.

[en] We measured differential cross sections and photon beam asymmetries for the γ-vectorp → K+Λ and γ-vectorp → K+Σ0 reactions at forward angles by using linearly polarized photons ranged from 1.5 GeV to 2.4 GeV at the SPring-8/LEPS facility. The photon beam asymmetries for both the reactions have been found to be positive and increase with the photon energy. The resonance-like structure found in the CLAS and SAPHIR data was seen in differential cross sections for the K+Λ reaction. The differential cross sections indicate the forward peaking for the K+Λ reaction, but not for the K+Σ0 reaction

[en] Photon beam asymmetries for the γ->p->K+Λ and γ->p->K+Σ0 reactions have been measured for the photon energy range from 1.5 GeV to 2.4 GeV and for the angular range of 0^oΘcmK+60^o at the SPring-8/LEPS facility. The observed asymmetries are found to be positive and increase with increasing the photon energy. Present theoretical calculations do not reproduce the data. To extend our knowledge on the K+ photoproduction mechanism including the effect of nucleon resonances, further theoretical development is required to fit both the cross section and asymmetry data

No abstract available

[en] The binding energy of ⁷_ΛHe has been obtained for the first time with reaction spectroscopy using the (e, e'K⁺) reaction at Jefferson Lab's Hall C. A comparison among the binding energies of the A = 7 T = l iso-triplet hypernuclei, ⁷_ΛHe, ⁷_ΛLi*and ⁷_ΛBe, is made and possible charge symmetry breaking (CSB) in the ΛN potential is discussed. For ⁷_ΛHe and ⁷_ΛBe, the shifts in binding energies are opposite to those predicted by a recent cluster model calculation, which assumes that the unexplained part of the binding energy difference between ⁴_ΛH and ⁴_ΛHe, is due to the CSB of the ΛN potential. Further examination of CSB in light hypernuclear systems is required both experimentally and theoretically.

[en] The BNL-AGS/E929 experiment was carried out to study energy levels of the _Λ¹³C hypernucleus by a gamma-ray spectroscopy. Energy splitting of the spin-orbit doublets, ((1)/(2))^- and ((3)/(2))^- states, was estimated precisely. The excitation energy of the 1st ((3)/(2))⁺ state was also measured. We discuss the symmetric and the anti-symmetric spin-orbit interactions between a Λ particle and a nucleon from the measurement

[en] The GeV photon beam at SPring-8 is produced by backward-Compton scattering of laser photons from 8 GeV electrons. The maximum energy of the photon will be above 3 GeV, and the beam intensity will be 10⁷ photons/sec. Polarization of the photon beam will be 100 % at the maximum energy with fully polarized laser photons. We report the outline of the quark nuclear physics project with this high-quality high-intensity beam