2,528 research outputs found
Pionic Atom Spectroscopy in the (d,3He) reaction at finite angles
We study the formation of deeply bound pionic atoms in the (d,3He) reactions
theoretically and show the energy spectra of the emitted 3He at finite angles,
which are expected to be observed experimentally. We find that the different
combinations of the pion-bound and neutron-hole states dominate the spectra at
different scattering angles because of the matching condition of the reaction.
We conclude that the observation of the (d,3He) reaction at finite angles will
provide the systematic information of the pionic bound states in each nucleus
and will help to develop the study of the pion properties and the partial
restoration of chiral symmetry in nuclei.Comment: 7 pages, 4 figures, 1 tabl
Manipulating transgenes using a chromosome vector
Recent technological advances have enabled us to visualize the organization and dynamics of local chromatin structures; however, the comprehensive mechanisms by which chromatin organization modulates gene regulation are poorly understood. We designed a human artificial chromosome vector that allowed manipulation of transgenes using a method for delivering chromatin architectures into different cell lines from human to fish. This methodology enabled analysis of de novo construction, epigenetic maintenance and changes in the chromatin architecture of specific genes. Expressive and repressive architectures of human STAT3 were established from naked DNA in mouse embryonic stem cells and CHO cells, respectively. Delivery of STAT3 within repressive architecture to embryonic stem cells resulted in STAT3 activation, accompanied by changes in DNA methylation. This technology for manipulating a single gene with a specific chromatin architecture could be utilized in applied biology, including stem cell science and regeneration medicine
Measurement of Positronium hyperfine splitting with quantum oscillation
Interference between different energy eigenstates in a quantum system results
in an oscillation with a frequency which is proportional to the difference in
energy between the states. Such an oscillation is observable in polarized
positronium when it is placed in a magnetic field. In order to measure the
hyperfine splitting of positronium, we perform the precise measurement of this
oscillation using a high quality superconducting magnet and fast
photon-detectors. A result of ~GHz is obtained which is consistent with both theoretical
calculations and previous precise measurements.Comment: 4 figures accepted by Phys. Lett.
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