The China Jinping Underground Laboratory(CJPL), which has the lowest cosmic-ray muon flux and the lowest reactor neutrino flux of any laboratory, is ideal to carry out low-energy neutrino experiments. With two detecto...The China Jinping Underground Laboratory(CJPL), which has the lowest cosmic-ray muon flux and the lowest reactor neutrino flux of any laboratory, is ideal to carry out low-energy neutrino experiments. With two detectors and a total fiducial mass of 2000 tons for solar neutrino physics(equivalently, 3000 tons for geo-neutrino and supernova neutrino physics), the Jinping neutrino experiment will have the potential to identify the neutrinos from the CNO fusion cycles of the Sun, to cover the transition phase for the solar neutrino oscillation from vacuum to matter mixing, and to measure the geo-neutrino flux, including the Th/U ratio. These goals can be fulfilled with mature existing techniques. Efforts on increasing the target mass with multi-modular neutrino detectors and on developing the slow liquid scintillator will increase the Jinping discovery potential in the study of solar neutrinos,geo-neutrinos, supernova neutrinos, and dark matter.展开更多
We propose a two-component dark matter explanation to the EDGES 21 cm anomalous signal.The heavier dark matter component is long-lived,and its decay is primarily responsible for the relic abundance of the lighter dark...We propose a two-component dark matter explanation to the EDGES 21 cm anomalous signal.The heavier dark matter component is long-lived,and its decay is primarily responsible for the relic abundance of the lighter dark matter,which is millicharged.To evade the constraints from CMB,underground dark matter direct detection,and XQC experiments,the lifetime of the heavier dark matter has to be larger than 0.1τU,whereτU is the age of the universe.Our model provides a viable realization of the millicharged dark matter model to explain the EDGES 21 cm signal,since the minimal model in which the relic density is generated via thermal freeze-out has been ruled out by various constraints.展开更多
We present a dark matter model to explain the excess events in the electron recoil data recently reported by the Xenon1 T experiment. In our model, dark matter χ annihilates into a pair of on-shell particles Φ, whic...We present a dark matter model to explain the excess events in the electron recoil data recently reported by the Xenon1 T experiment. In our model, dark matter χ annihilates into a pair of on-shell particles Φ, which subsequently decay into the ψψ final state;ψ interacts with electrons to generate the observed excess events. Because of the mass hierarchy, the velocity of ψ can be rather large and can have an extended distribution, providing a good fit to the electron recoil energy spectrum. We estimate the flux of ψ from dark matter annihilations in the galaxy and further determine the interaction cross section, which is sizable but sufficiently small to allow ψ to penetrate the rocks to reach the underground labs.展开更多
基金Supported by the National Natural Science Foundation of China(11235006,11475093,11135009,11375065,11505301,and11620101004)the Tsinghua University Initiative Scientific Research Program(20121088035,20131089288,and 20151080432)+3 种基金the Key Laboratory of Particle&Radiation Imaging(Tsinghua University)the CAS Center for Excellence in Particle Physics(CCEPP)U.S.National Science Foundation Grant PHY-1404311(Beacom)U.S.Department of Energy under contract DE-AC02-98CH10886(Yeh)
文摘The China Jinping Underground Laboratory(CJPL), which has the lowest cosmic-ray muon flux and the lowest reactor neutrino flux of any laboratory, is ideal to carry out low-energy neutrino experiments. With two detectors and a total fiducial mass of 2000 tons for solar neutrino physics(equivalently, 3000 tons for geo-neutrino and supernova neutrino physics), the Jinping neutrino experiment will have the potential to identify the neutrinos from the CNO fusion cycles of the Sun, to cover the transition phase for the solar neutrino oscillation from vacuum to matter mixing, and to measure the geo-neutrino flux, including the Th/U ratio. These goals can be fulfilled with mature existing techniques. Efforts on increasing the target mass with multi-modular neutrino detectors and on developing the slow liquid scintillator will increase the Jinping discovery potential in the study of solar neutrinos,geo-neutrinos, supernova neutrinos, and dark matter.
基金Supported in part by the National Natural Science Foundation of China(11775109)。
文摘We propose a two-component dark matter explanation to the EDGES 21 cm anomalous signal.The heavier dark matter component is long-lived,and its decay is primarily responsible for the relic abundance of the lighter dark matter,which is millicharged.To evade the constraints from CMB,underground dark matter direct detection,and XQC experiments,the lifetime of the heavier dark matter has to be larger than 0.1τU,whereτU is the age of the universe.Our model provides a viable realization of the millicharged dark matter model to explain the EDGES 21 cm signal,since the minimal model in which the relic density is generated via thermal freeze-out has been ruled out by various constraints.
基金Supported in part by the National Natural Science Foundation of China(U1738134,11775109)。
文摘We present a dark matter model to explain the excess events in the electron recoil data recently reported by the Xenon1 T experiment. In our model, dark matter χ annihilates into a pair of on-shell particles Φ, which subsequently decay into the ψψ final state;ψ interacts with electrons to generate the observed excess events. Because of the mass hierarchy, the velocity of ψ can be rather large and can have an extended distribution, providing a good fit to the electron recoil energy spectrum. We estimate the flux of ψ from dark matter annihilations in the galaxy and further determine the interaction cross section, which is sizable but sufficiently small to allow ψ to penetrate the rocks to reach the underground labs.
