Browsing by Author "Lin, Yen-Hsun"

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Complementary test of the dark matter self-interaction in dark U(1) model by direct and indirect dark matter detection
(2016-01-01)
Chen, Chian-Shu
;
Lin, Guey-Lin
;
Lin, Yen-Hsun
;
物理研究所
;
Institute of Physics
The halo dark matter (DM) can be captured by the Sun if its final velocity after the collision with a nucleus in the Sun is less than the escape velocity. We consider a selfinteracting dark matter (SIDM) model where U(1) gauge symmetry is introduced to account for the DM self-interaction. Such a model naturally leads to isospin violating DM nucleon interaction, although isospin symmetric interaction is still allowed as a special case. We present the IceCube-PINGU 2a sensitivity to the parameter range of the above model with 5 years of search for neutrino signature from DM annihilation in the Sun. This indirect detection complements the direct detection by probing those SIDM parameter ranges which are either the region for very small rnx or the region opened up due to isospin violations.
Complementary Test of the Dark Matter Self-Interaction in Dark U(1) Model by Direct and Indirect Detection
(2016-01-01)
Chen, Chian-Shu
;
Lin, Yen-Hsun
;
Lin, Guey-Lin
;
物理研究所
;
Institute of Physics
The halo dark matter (DM) can be captured by the Sun if its final velocity after the collision with a nucleus in the Sun is less than the escape velocity. We consider a selfinteracting dark matter (SIDM) model where U(1) gauge symmetry is introduced to account for the DM self-interaction. Such a model naturally leads to isospin violating DM- nucleon interaction, although isospin symmetric interaction is still allowed as a special case. We present the IceCube-PINGU 2 sigma sensitivity to the parameter range of the above model with 5 years of search for neutrino signature from DM annihilation in the Sun. This indirect detection complements the direct detection by probing those SIDM parameter ranges which are either the region for very small m(chi) or the region opened up due to isospin violations.
Neutrino physics with JUNO
(2016-03)
An, Fengpeng
;
An, Guangpeng
;
An, Qi
;
Antonelli, Vito
;
Baussan, Eric
The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multipurpose underground liquid scintillator detector, was proposed with the determination of the neutrino mass hierarchy (MH) as a primary physics goal. The excellent energy resolution and the large fiducial volume anticipated for the JUNO detector offer exciting opportunities for addressing many important topics in neutrino and astro-particle physics. In this document, we present the physics motivations and the anticipated performance of the JUNO detector for various proposed measurements. Following an introduction summarizing the current status and open issues in neutrino physics, we discuss how the detection of antineutrinos generated by a cluster of nuclear power plants allows the determination of the neutrino MH at a 3-4 sigma significance with six years of running of JUNO. The measurement of antineutrino spectrum with excellent energy resolution will also lead to the precise determination of the neutrino oscillation parameters sin(2) theta(12), Delta m(21)(2), and vertical bar Delta m(ee)(2)vertical bar to an accuracy of better than 1%, which will play a crucial role in the future unitarity test of the MNSP matrix. The JUNO detector is capable of observing not only antineutrinos from the power plants, but also neutrinos/antineutrinos from terrestrial and extra-terrestrial sources, including supernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos, atmospheric neutrinos, and solar neutrinos. As a result of JUNO\'s large size, excellent energy resolution, and vertex reconstruction capability, interesting new data on these topics can be collected. For example, a neutrino burst from a typical core-collapse supernova at a distance of 10 kpc would lead to similar to 5000 inverse-beta-decay events and similar to 2000 all-flavor neutrino-proton ES events in JUNO, which are of crucial importance for understanding the mechanism of supernova explosion and for exploring novel phenomena such as collective neutrino oscillations. Detection of neutrinos from all past core-collapse supernova explosions in the visible universe with JUNO would further provide valuable information on the cosmic star-formation rate and the average core-collapse neutrino energy spectrum. Antineutrinos originating from the radioactive decay of uranium and thorium in the Earth can be detected in JUNO with a rate of similar to 400 events per year, significantly improving the statistics of existing geoneutrino event samples. Atmospheric neutrino events collected in JUNO can provide independent inputs for determining the MH and the octant of the theta(23) mixing angle. Detection of the Be-7 and B-8 solar neutrino events at JUNO would shed new light on the solar metallicity problem and examine the transition region between the vacuum and matter dominated neutrino oscillations. Regarding light sterile neutrino topics, sterile neutrinos with 10-(5) eV(2) < Delta m(41)(2) < 10(-2) and a sufficiently large mixing angle theta(14) could be identified through a precise measurement of the reactor antineutrino energy spectrum. Meanwhile, JUNO can also provide us excellent opportunities to test the eV-scale sterile neutrino hypothesis, using either the radioactive neutrino sources or a cyclotron-produced neutrino beam. The JUNO detector is also sensitive to several other beyondthe-standard-model physics. Examples include the search for proton decay via the p -> K++ <(v)over bar> decay channel, search for neutrinos resulting from dark-matter annihilation in the Sun, search for violation of Lorentz invariance via the sidereal modulation of the reactor neutrino event rate, and search for the effects of non-standard interactions. The proposed construction of the JUNO detector will provide a unique facility to address many outstanding crucial questions in particle and astrophysics in a timely and cost-effective fashion. It holds the great potential for further advancing our quest to understanding the fundamental properties of neutrinos, one of the building blocks of our Universe.
Probing dark matter self-interaction in the Sun with IceCube-PINGU
(2014-10-01)
Chen, Chian-Shu
;
Lee, Fei-Fan
;
Lin, Guey-Lin
;
Lin, Yen-Hsun
;
物理研究所
We study the capture, annihilation and evaporation of dark matter (DM) inside the Sun. It has been shown that the DM self-interaction can increase the DM number inside the Sun. We demonstrate that this enhancement becomes more significant in the regime of small DM mass, given a fixed DM self-interaction cross section. This leads to the enhancement of neutrino flux from DM annihilation. On the other hand, for DM mass as low as as a few GeVs, not only the DM-nuclei scatterings can cause the DM evaporation, DM self-interaction also provides non-negligible contributions to this effect. Consequently, the critical mass for DM evaporation (typically 3 similar to 4 GeV without the DM self-interaction) can be slightly increased. We discuss the prospect of detecting DM self-interaction in IceCube-PINGU using the annihilation channels chi chi -> tau(+)tau(-), nu(nu) over bar as examples. The PINGU sensitivities to DM self-interaction cross section sigma(chi chi) are estimated for track and cascade events.
Probing the coupling of heavy dark matter to nucleons by detecting neutrino signature from the Earth's core
(2015-02-05)
Lin, Guey-Lin
;
Lin, Yen-Hsun
;
Lee, Fei-Fan
;
物理研究所
;
Institute of Physics
We argue that the detection of the neutrino signature from the Earth's core can effectively probe the coupling of heavy dark matter (m(chi) > 10(4) GeV) to nucleons. We first note that direct searches for dark matter (DM) in such a mass range provide much less stringent constraint than the constraint provided by such searches for m(chi) similar to 100 GeV. Furthermore, the energies of neutrinos arising from DM annihilation inside the Sun cannot exceed a few TeVs at the Sun's surface due to the attenuation effect. Therefore, the sensitivity to the heavy DM coupling is lost. Finally, the detection of the neutrino signature from the Galactic halo can only probe DM annihilation cross sections. We present neutrino event rates in IceCube and KM3NeT arising from the neutrino flux produced by annihilation of Earth-captured DM heavier than 10(4) GeV. The IceCube and KM3NeT sensitivities to spin-independent DM-proton scattering cross section sigma(chi p) in this mass range are presented for both isospin-symmetric and isospin-violating cases.
The 17 MeV anomaly in beryllium decays and U(1) portal to dark matter
(2017-11-10)
Chen, Chian-Shu
;
Lin, Guey-Lin
;
Lin, Yen-Hsun
;
Xu, Fanrong
;
物理研究所
The experiment of Krasznahorkay et al. observed the transition of a Be-8 excited state to its ground state and accompanied by an emission of an e(+) e(-) pair with 17 MeV invariant mass. This 6.8 sigma anomaly can be fitted by a new light gauge boson. We consider the new particle as a U(1) gauge boson, Z', which plays as a portal linking dark sector and visible sector. In particular, we study the new U(1) gauge symmetry as a hidden or nonhidden group separately. The generic hidden U(1) model, referred to as dark Z model, is excluded by imposing various experimental constraints. On the other hand, a nonhidden Z' is allowed due to the additional interactions between Z' and Standard Model fermions. We also study the implication of the dark matter direct search on such a scenario. We found that the search for the DM-nucleon scattering cannot probe the parameter space that is allowed by Be-8-anomaly for the range of DM mass above 500 MeV. However, the DM-electron scattering for DM between 20 MeV and 50 MeV can test the underlying U(1) portal model using the future Si and Ge detectors with the 5e(-) threshold charges.
The Dark Matter Self-Interaction and Its Impact on the Critical Mass for Dark Matter Evaporations Inside the Sun
(2016-04-06)
Chen, Chian-Shu
;
Lee, Fei-Fan
;
Lin, Guey-Lin
;
Lin, Yen-Hsun
;
物理研究所
We study the capture, annihilation and evaporation of dark matter (DM) inside the Sun. It has been shown that the DM self-interaction can increase the DM number inside the Sun. We demonstrate that this enhancement becomes more significant in the regime of small DM mass, given a fixed DM self-interaction cross section. This leads to the enhancement of neutrino flux from DM annihilation. On the other hand, for DM mass as low as as a few GeVs, not only the DM-nuclei scatterings can cause the DM evaporation, DM self-interaction also provides non-negligible contributions to this effect. Consequently, the critical mass for DM evaporation (typically 3 similar to 4 GeV without the DM self-interaction) can be slightly increased. We discuss the prospect of detecting DM self-interaction in IceCube-PINGU using the annihilation channels chi chi -> tau(+)tau(-), nu(nu) over bar as examples. The PINGU sensitivities to DM self-interaction cross section sigma(chi chi) are estimated for track and cascade events.
The Dark Matter Self-Interaction and Its Impact on the Critical Mass for Dark Matter Evaporations Inside the Sun
(2016-04-01)
Chen, Chian-Shu
;
Lee, Fei-Fan
;
Lin, Guey-Lin
;
Lin, Yen-Hsun
;
物理研究所
We study the capture, annihilation and evaporation of dark matter (DM) inside the Sun. It has been shown that the DM self-interaction can increase the DM number inside the Sun. We demonstrate that this enhancement becomes more significant in the regime of small DM mass, given a fixed DM self-interaction cross section. This leads to the enhancement of neutrino flux from DM annihilation. On the other hand, for DM mass as low as as a few GeVs, not only the DM-nuclei scatterings can cause the DM evaporation, DM self-interaction also provides non-negligible contributions to this effect. Consequently, the critical mass for DM evaporation (typically 3 similar to 4 GeV without the DM self-interaction) can be slightly increased. We discuss the prospect of detecting DM self-interaction in IceCube-PINGU using the annihilation channels chi chi -> tau(+)tau(-), nu(nu) over bar as examples. The PINGU sensitivities to DM self-interaction cross section sigma(chi chi) are estimated for track and cascade events.
Thermal transport of the solar captured dark matter and its impact on the indirect dark matter search
(2016-12)
Chen, Chian-Shu
;
Lin, Guey-Lin
;
Lin, Yen-Hsun
;
物理研究所
;
Institute of Physics
We study the thermal transport occurring in the system of solar captured dark matter (DM) and explore its impact on the DM indirect search signal. We particularly focus on the scenario of self-interacting DM (SIDM). The flows of energies in and out of the system are caused by solar captures via DM-nucleon and DM-DM scatterings, the energy dissipation via DM annihilation, and the heat exchange between DM and solar nuclei. We examine the DM temperature evolution and demonstrate that the DM temperature can be higher than the core temperature of the Sun if the DM-nucleon cross section is sufficiently small such that the energy flow due to DM self-interaction becomes relatively important. We argue that the correct DM temperature should be used for accurately predicting the DM annihilation rate, which is relevant to the DM indirect detection. (C) 2016 Elsevier B.V.All rights reserved.
Thermal transport of the solar captured dark matter and its impact on the indirect dark matter search
(2016-12)
Chen, Chian-Shu
;
Lin, Guey-Lin
;
Lin, Yen-Hsun
;
物理研究所
;
Institute of Physics
We study the thermal transport occurring in the system of solar captured dark matter (DM) and explore its impact on the DM indirect search signal. We particularly focus on the scenario of self-interacting DM (SIDM). The flows of energies in and out of the system are caused by solar captures via DM-nucleon and DM-DM scatterings, the energy dissipation via DM annihilation, and the heat exchange between DM and solar nuclei. We examine the DM temperature evolution and demonstrate that the DM temperature can be higher than the core temperature of the Sun if the DM-nucleon cross section is sufficiently small such that the energy flow due to DM self-interaction becomes relatively important. We argue that the correct DM temperature should be used for accurately predicting the DM annihilation rate, which is relevant to the DM indirect detection. (C) 2016 Elsevier B.V.All rights reserved.
Thermal transport of the solar captured dark matter and its implication
(2016-01-01)
Lin, Yen-Hsun
;
Chen, Chian-Shu
;
Lin, Guey-Lin
;
物理研究所
;
Institute of Physics
We study the thermal transport occurring in the system of solar captured dark matter (DM) and explore its impact on the DM indirect search signal. We particularly focus on the scenario of self-interacting DM (SIDM). The flows of energies in and out of the system are caused by solar captures via DM-nucleon and DM-DM scatterings, the energy dissipation via DM annihilation, and the heat exchange between DM and solar nuclei.We examine the DM temperature evolution and demonstrate that the DM temperature can be higher than the core temperature of the Sun if the DM-nucleon cross section is sufficiently small such that the energy flow due to DM self-interaction becomes relatively important. We argue that the correct DM temperature should be used for accurately predicting the DM annihilation rate, which is relevant to the DM indirect detection.