41 research outputs found
Phenomenology of NMSSM in TeV scale mirage mediation
We study the next-to-minimal supersymmetric standard model (NMSSM) with the
TeV scale mirage mediation, which is known as a solution for the little
hierarchy problem in supersymmetry. Our previous study showed that 125 GeV
Higgs boson is realized with O(10) % fine-tuning for 1.5 TeV gluino (1 TeV
stop) mass. The term could be as large as 500 GeV without sacrificing the
fine-tuning thanks to a cancellation mechanism. The singlet-doublet mixing is
suppressed by . In this paper, we further extend this analysis. We
argue that approximate scale symmetries play a role behind the suppression of
the singlet-doublet mixing. They reduce the mixing matrix to a simple form that
is useful to understand the results of the numerical analysis. We perform a
comprehensive analysis of the fine-tuning including the singlet sector by
introducing a simple formula for the fine-tuning measure. This shows that the
singlet mass of the least fine-tuning is favored by the LEP anomaly for
moderate . We also discuss prospects for the precision measurements
of the Higgs couplings at LHC and ILC and direct/indirect dark matter searches
in the model.Comment: 47 pages, 46 figures, version accepted by JHE
High-resolution multislice X-ray ptychography of extended thick objects
We report the first demonstration of hard x-ray ptychography using a multislice approach, which can solve the problem of the limited spatial resolution under the projection approximation. We measured ptychographic diffraction patterns of a two-layered object with a 105 μm gap using 7 keV focused coherent x rays. We successfully reconstructed the phase map of each layer at ∼50 nm resolution using a multislice approach, while the resolution was worse than ∼192 nm under the projection approximation. The present method has the potential to enable the three-dimensional high-resolution observation of extended thick specimens in materials science and biology.Akihiro Suzuki, Shin Furutaku, Kei Shimomura, Kazuto Yamauchi, Yoshiki Kohmura, Tetsuya Ishikawa, and Yukio Takahashi, Phys. Rev. Lett. 112, 053903, 2014
Oxygen-diffusion-driven oxidation behavior and tracking areas visualized by X-ray spectro-ptychography with unsupervised learning
Cerium–zirconium solids are key materials in heterogeneous catalysis but understanding oxygen storage and diffusion in bulk samples is a challenge. Here the authors use three-dimensional hard X-ray spectro-ptychography and unsupervised learning to achieve nanoscale chemical imaging of reaction events
CCN3 and bone marrow cells
CCN3 expression was observed in a broad variety of tissues from the early stage of development. However, a kind of loss of function in mice (CCN3 del VWC domain -/-) demonstrated mild abnormality, which indicates that CCN3 may not be critical for the normal embryogenesis as a single gene. The importance of CCN3 in bone marrow environment becomes to be recognized by the studies of hematopoietic stem cells and Chronic Myeloid Leukemia cells. CCN3 expression in bone marrow has been denied by several investigations, but we found CCN3 positive stromal and hematopoietic cells at bone extremities with a new antibody although they are a very few populations. We investigated the expression pattern of CCN3 in the cultured bone marrow derived mesenchymal stem cells and found its preference for osteogenic differentiation. From the analyses of in vitro experiment using an osteogenic mesenchymal stem cell line, Kusa-A1, we found that CCN3 downregulates osteogenesis by two different pathways; suppression of BMP and stimulation of Notch. Secreted CCN3 from Kusa cells inhibited the differentiation of osteoblasts in separate culture, which indicates the paracrine manner of CCN3 activity. CCN3 may also affect the extracellular environment of the niche for hematopoietic stem cells
Dark-field X-ray ptychography: Towards high-resolution imaging of thick and unstained biological specimens
The phase shift of light or electrons in objects is now necessary for probing weak-phase objects such as unstained biological specimens. Optical microscopy (OM) and transmission electron microscopy (TEM) have been used to observe weak-phase objects. However, conventional OM has low spatial resolution and TEM is limited to thin specimens. Here, we report on the development of dark-field X-ray ptychography, which combines X-ray ptychography and X-ray in-line holography, to observe weak-phase objects with a phase resolution better than 0.01 rad, a spatial resolution better than 15 nm, and a field of view larger than 5 mu m. We apply this method to the observation of both the outline and magnetosomes of the magnetotactic bacteria MO-1. Observation of thick samples with high resolution is expected to find broad applications in not only biology but also materials science