2014 Fiscal Year Annual Research Report
素粒子、宇宙等の広域分野の研究に基づいた暗黒物質の統一的理解
| Project/Area Number |
14J08099
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| Research Institution | The University of Tokyo |
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Principal Investigator |
LIEW SENGPEI 東京大学, 理学系研究科, 特別研究員(DC1)
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| Project Period (FY) |
2014-04-25 – 2017-03-31
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| Keywords | 暗黒物質 / コライダー物理 / 宇宙線物理 |
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| Outline of Annual Research Achievements |
The focus of my research this year is on the properties of dark matter.
Monochromatic X-ray line could be a signature of annihilation or decay of dark matter. Such signal are recently found to be coming from the a few galaxy clusters at energy around 3.5 keV. Two independent experimental group have found the signal using different telescope, making this signal unlikely to be falsified. I have shown that axino (supersymmetric partner of axion) dark matter with trilinear R-parity violation is capable of explaining the observed X-ray line. This work is published in the Journal of Cosmological and Astrophysical Physics.
Dark matter may also be detectable through the observation of the recoil of nuclei that scatters elastically with dark matter. Some experimental groups have claimed to observe dark matter-nucleon scattering events for dark matter of mass around 10 GeV. However, other experiments such as XENON100, LUX and recently SuperCDMS have ruled out most parameter regions claimed to be yielding positive results. As XENON100 and LUX utilize xenon nuclei for detection and find no dark matter signals, it is possible that the couplings of dark matter to neutron and proton are different in such a way that dark matter interacts weakly to xenon nuclei. This could reconcile the results of several direct detection experiments. This is called isospin-violating dark matter. We have studied a simplified model of such dark matter. We have also studied the capability of testing the model at the LHC. The work is reported in the Journal of High Energy Physics.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
I have proposed a new model of dark matter that is able to explain the anomalous excess of X-ray line, in line with my original proposal of studying possible detection of indirect astrophysical signals of dark matter.
I have also published a paper on the isospin-violating dark matter as proposed. Based on a collaboration with other researchers, we have found interesting possibilities to generalize this work. I intend to extend the work to a more complete and systematic study.
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| Strategy for Future Research Activity |
LHC is capable of studying a wide range of new dark matter models, other than the often-studied models of supersymmetry or extra dimensions. I intend to study in a more general and systematic fashion on the relationship between simplified dark matter models and mono-events at the LHC.
Two Higgs doublet model (2HDM) with dark matter is a well-known example of dark matter models, but a general study seems to be lacking in the literature. I intend to launch a global analysis on the model, considering the interplay between collider searches, direct and indirect detection.
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Research Products
(4 results)
