[en] For the early detection of cancer, we have developed a method to locate tumours modified by iodine contrast agent in a human body with a small number of X-ray transmission images. A planar type transXend detector was used to measure X-ray transmitted through an acrylic phantom with iodine tincture and an aluminum rod. The thickness distributions of iodine, aluminum, and acrylic were estimated and the thickness distributions for the materials were reconstructed. (author)

[en] With the final aim of achieving iodine contrast-enhanced cancer screening examinations with low dose exposure, we reconstructed tomographic images of material distributions from X-ray transmission measurements obtained from a small number of measurement directions. This method used a planar-type four-channel 'transXend' detector. The phantom was subjected to four different X-ray spectra tailored by filters, and the X-rays were measured by a flat panel detector. The X-ray attenuation by the phantom was reproduced according to attenuations by acrylic, iodine, and aluminum, which acted as substitutes for normal tissue, iodine contrast agent, and bone, respectively. The material thickness distributions obtained were used for tomographic image reconstruction of the material distribution. The quality of iodine tomographic images is discussed as a function of the number of measurement directions. (author)

[en] We reanalyze the D·+π- mass spectrum from CLEO II by the VMW method in order to examine the existence of a chiral axial-vector state, which is predicted in a covariant level-classification scheme recently proposed, other than normal orbitally-excited P-wave states in the D meson system. A result of the present analysis seems to suggest that there exists an extra axial-vector meson, in addition to the two normal ones, in a similar mass region

[en] In a covariant level-classification scheme of hadrons proposed recently, the existence of 'chiral particles', scalar and axial-vector mesons as the partners of the ground-state pseudo-scalar and vector mesons, respectively, were predicted in D and B meson systems, realizing a linear representation of chiral symmetry concerning the light quark. In this work we reanalyze the D*π mass spectra obtained through Υ(4S) and Z⁰ decay and the Bπ spectra obtained through Z⁰ decay to show the possibility of the existence of D₁^χ and B₀^χ, respectively. (author)

[en] In a covariant level-classification scheme of hadrons proposed recently, the existence of ''chiral particles'', scalar and axial-vector mesons as the partners of the ground-state pseudo-scalar and vector mesons, respectively, were predicted in D and B meson systems, realizing a linear representation of chiral symmetry concerning the light quarks. In this work we reanalyze the D*π mass spectra obtained through Υ(4S) and Z⁰ decay and the Bπ spectra obtained through Z⁰ decay to show the possibility of the existence of D₁^χ and B₀^χ, respectively. This talk is a review of essential points of our previous work. (author)