1,355 research outputs found
Extending the LHC Reach for New Physics with Sub-Millimeter Displaced Vertices
Particles with a sub-millimeter decay length appear in many models of physics
beyond the Standard Model. However, their longevity has been often ignored in
their LHC searches and they have been regarded as promptly-decaying particles.
In this letter, we show that, by requiring displaced vertices on top of the
event selection criteria used in the ordinary search strategies for
promptly-decaying particles, we can considerably extend the LHC reach for
particles with a decay length of . We discuss a way of
reconstructing sub-millimeter displaced vertices by exploiting the same
technique used for the primary vertex reconstruction on the assumption that the
metastable particles are always pair-produced and their decay products contain
high- jets. We show that, by applying a cut based on displaced
vertices on top of standard kinematical cuts for the search of new particles,
the LHC reach can be significantly extended if the decay length is . In addition, we may measure the lifetime of the target
particle through the reconstruction of displaced vertices, which plays an
important role in understanding the new physics behind the metastable
particles.Comment: 18 pages, 6 figure
Research on ignition and flame spread of solid materials in Japan
Fire safety is one of the main concerns for crewed missions such as the space station. Materials used in spacecraft may burn even if metalic. There are severe restrictions on the materials used in spacecraft from the view of fire safety. However, such restrictions or safety standards are usually determined based on experimental results under normal gravity, despite large differences between the phenomena under normal and microgravity. To evaluate the appropriateness of materials for use in space, large amount of microgravity fire-safety combustion data is urgently needed. Solid material combustion under microgravity, such as ignition and flame spread, is a relatively new research field in Japan. As the other reports in this workshop describe, most of microgravity combustion research in Japan is droplet combustion as well as some research on gas phase combustion. Since JAMIC, the Japan Microgravity Center, (which offers 10 seconds microgravity time) opened in 1992, microgravity combustion research is robust, and many drop tests relating to solid combustion (paper combustion, cotton string combustion, metal combustion with Aluminium or Magnesium) have been performed. These tests proved that the 10 seconds of microgravity time at JAMIC is useful for solid combustion research. Some experiments were performed before JAMIC opened. For example, latticed paper was burned under microgravity by using a 50 m drop tower to simulate porous material combustion under microgravity. A 50 m tower provides only 2 seconds microgravity time however, and it was not long enough to investigate the solid combustion phenomena
Scalar Transfer across a Turbulent/non-turbulent Interface in a Planar Jet
This fluid dynamics video is an entry for the Gallery of Fluid Motion of the
66th Annual Meeting of the APS-DFD. In this video, the scalar transfer across
the turbulent/non-turbulent (T/NT) interface in a planar jet is investigated by
using a direct numerical simulation. Visualization of the scalar flux across
the T/NT interface shows that the diffusive species premixed in the ambient
flow is transferred into the turbulent region mainly across the leading edge
(Here, the leading edge is the T/NT interface across which the turbulent fluid
turns into the non-turbulent fluid in the streamwise direction).Comment: The fluid dynamics video for an entry for the Gallery of Fluid Motion
of the 66th Annual Meeting of the APS-DFD is include
Assessment of natural hazards due to a category-5 extreme typhoon under global warming by dynamical downscaling experiments
The 7th International Conference on Water Resources and Environment Research (ICWRER2016), Kyoto TERUSA, Kyoto, Japan, 5-9 June 201
A case of follicular lymphoma complicated with mesenteric panniculitis
Mesenteric panniculitis (MP) is a rare disease occasionally complicated with lymphoma. A 55-year old female presented with MP accompanied by malignant lymphoma. This patient was first treated for follicular lymphoma and subsequently for panniculitis. After 6 courses of R-CHOP chemotherapy, the treatment response was partial. An additional course of salvage chemotherapy led to a complete response. Since the mesenteric mass progressed simultaneously with the regression of other lymphoma lesions, we performed a biopsy of the mesenteric mass and pathologically confirmed an MP lesion without lymphoma. Subsequent high-dose chemotherapy led to CR and the MP lesion remained stable. In the present case, MP progressed with chemotherapy. We concluded that mesenteric lesions suspected of progressing or recurring should be diagnosed pathologically even if asymptomatic
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