Browsing by Author "Tsai, Yue-Lin Sming"

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Constraining dark matter capture and annihilation cross sections by searching for neutrino signature from the Earth's core
(2014-01-06)
Lee, Fei-Fan
;
Lin, Guey-Lin
;
Tsai, Yue-Lin Sming
;
物理研究所
;
Institute of Physics
We study the sensitivity of IceCube/DeepCore detector to dark matter annihilations in the Earth's core. We focus on annihilation modes chi chi -> nu(nu) over cap, tau(+)tau(-), h (h) over cap, and W+W-. Both track and cascade events are considered in our analysis. By fixing the dark matter annihilation cross section at some nominal values, we study the sensitivity of the IceCube/DeepCore detector to dark matter spin- independent cross section sigma(SI)(p) for m(chi) ranging from few tens of GeV to 10 TeV. This sensitivity is compared with the existing IceCube 79-string constraint on the same cross section, which was obtained by searching for dark matter annihilations in the Sun. We compare this sensitivity to dark matter direct detection results as well, in particular the XENON100 (2012) limit and the parameter regions preferred by DAMA and CRESST- II experiments. We also present IceCube/DeepCore sensitivity to hs.i as a function of m(chi) by fixing sigma(SI)(p) at XENON100 (2012) and XENON1T limits, respectively. This sensitivity is compared with the preferred dark matter parameter range derived from the combined fitting to PAMELA and AMS02 positron fraction data. We conclude that the search for dark matter annihilations in the Earth's core provides competitive constraints on sigma(SI)(p) and in the case of low- mass dark matter. Particularly, the expected constraint on sigma(SI)(p) for 5 years of data taking in IceCube/DeepCore is more stringent than the current IceCube 79- string limit mentioned above.
Dark Matter Induced Neutrino Signature in IceCube DeepCore Detector
(2014-01-01)
Lee, Fei-Fan
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Lin, Guey-Lin
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Tsai, Yue-Lin Sming
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物理研究所
;
Institute of Physics
The installation of DeepCore array significantly lowers IceCube\'s energy threshold to about 10 GeV and enhances the sensitivity of detecting neutrinos from annihilations and decays of light dark matter. To match this experimental development, we discuss decays of the event rate in DeepCore array due to neutrino flux produced by annihilations and galactic dark matter. This event rate is calculated with a 10 GeV threshold energy, which is smaller than the threshold energy taken in previous works. Taking into account the background event rate due to the atmospheric neutrino flux, we evaluate the sensitivity of DeepCore array for probing dark matter annihilation cross section and decay time. We compare our results with corresponding constraints derived from observations of WMAP, ACT and Fermi-LAT.
Sensitivities of the IceCube DeepCore detector to signatures of low-mass dark matter in the Galactic halo
(2013-01-02)
Lee, Fei-Fan
;
Lin, Guey-Lin
;
Tsai, Yue-Lin Sming
;
物理研究所
;
Institute of Physics
We discuss the event rate in the DeepCore array due to neutrino flux produced by annihilations and decays of Galactic dark matter. This event rate is calculated with a 10 GeV threshold energy, which is smaller than the threshold energy taken in previous works. Taking into account the background event rate due to the atmospheric neutrino flux, we evaluate the sensitivity of the DeepCore array for probing the dark matter annihilation cross section and decay time. The sensitivity studies include the annihilation modes chi chi -> b (b) over bar, tau(+)tau(-), mu(+)mu(-), and nu(nu) over bar, and decay modes chi -> b (b) over bar, tau(+)tau(-), mu(+)mu(-), and nu(nu) over bar. We compare our results with corresponding constraints derived from observations of WMAP, ACT, and Fermi-LAT. DOI: 10.1103/PhysRevD.87.025003