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(darkAI)Mapping the large-scale density field of Dark Matter using artificial intelligence

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 143-159页

作者： Zitong Wang Feng Shi Xiaohu Yang Qingyang Li Yanming Liu Xiaoping Li School of Aerospace Science and Technology Xidian UniversityXi’an 710126China Department of Astronomy School of Physics and Astronomyand Shanghai Key Laboratory for Particle Physics and CosmologyShanghai Jiao Tong UniversityShanghai 200240China Tsung-Dao Lee Institute and Key Laboratory for Particle Physics Astrophysics and CosmologyMinistry of EducationShanghai Jiao Tong UniversityShanghai 200240China Institute for Astronomy University of EdinburghRoyal ObservatoryEdinburgh EH93HJUnited Kingdom

Herein,we present a deep-learning technique for reconstructing the dark-matter density field from the redshift-space distribution of dark-matter halos.We built a UNet-architecture neural network and trained it using the COmoving Lagrangian Acceleration fast simulation,which is an approximation of the N-body simulation with 5123 particles in a box size of 500 h^(-1)Mpc.Further,we tested the resulting UNet model not only with training-like test samples but also with standard N-body simulations,such as the Jiutian simulation with 61443particles in a box size of 1000 h^(-1)Mpc and the ELUCID simulation,which has a different cosmology.The real-space dark-matter density fields in the three simulations can be reconstructed reliably with only a small reduction of the cross-correlation power spectrum at 1%and 10%levels at k=0.1 and 0.3 h Mpc-1,respectively.The reconstruction clearly helps to correct for redshift-space distortions and is unaffected by the different cosmologies between the training(Planck2018)and test samples(WMAP5).Furthermore,we tested the application of the UNet-reconstructed density field to obtain the velocity&tidal field and found that this approach provides better results compared with the traditional approach based on the linear bias model,showing a 12.2%improvement in the correlation slope and a 21.1%reduction in the scatter between the predicted and true velocities.Thus,our method is highly efficient and has excellent extrapolation reliability beyond the training set.This provides an ideal solution for determining the three-dimensional underlying density field from the plentiful galaxy survey data.

关键词： Dark Matter large-scale structure cosmology

Effects of Dark Matter on shadows and rings of Brane-World black holes illuminated by various accretions

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Science China(Physics,Mechanics & Astronomy) 2022年第9期65卷 27-43页

作者： Xiao-Xiong Zeng Ke-Jian He Guo-Ping Li State Key Laboratory of Mountain Bridge and Tunnel Engineering Chongqing Jiaotong UniversityChongqing 400074China Department of Mechanics Chongqing Jiaotong UniversityChongqing 400074China College of Physics Chongqing UniversityChongqing 401331China Physics and Space College China West Normal UniversityNanchong 637000China

In this study, by taking the accretions into account, the observed shadows and rings cast by the Brane-World black hole were numerically investigated when the observer was located at the cosmological horizon. The results showed that the radius rpof the photon sphere increased with the cosmological parameter α and Dark Matter parameter β, while the impact parameter bpdecreased with α and increased with β. For thin disk accretion, the total observed intensity is mainly composed of direct emission.Simultaneously, the lensing ring and photon ring have only small and negligible contributions, respectively. We also found that shadows and rings exhibit different and exciting features when the disk is located at different positions. For static and infalling spherical accretions, it is evident that the size of shadows is always the same for both accretions. This implies that shadows are only related to space-time geometry in this case. The luminosity of the shadow and photon sphere is closely associated with the Doppler effect and the emissivity per unit volume j(νe). In addition, the influence of Dark Matter and cosmological constant on the observed intensity of shadows and rings is carefully emphasized throughout this paper. Finally, we obtained the burring images of shadows and rings using the nominal resolution of the event horizon telescope. We also studied the upper limits of the X-clod Dark Matter parameter β using the data of the shadow of M87.

关键词： Dark Matter the accretion black hole shadow lensing and photon rings

High‑accuracy measurement of Compton scattering in germanium for Dark Matter searches

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Nuclear Science and Techniques 2022年第12期33卷 75-87页

作者： Hai‑Tao Jia Shin‑Ted Lin Shu‑Kui Liu Hsin‑Chang Chi Muhammed Deniz Chang‑Hao Fang Peng Gu Xi Jiang Yi‑Ke Shu Qian‑Yun Li Yu Liu Ren‑Ming‑Jie Li Chen‑Kai Qiao Chang‑Jian Tang Henry Tsz‑King Wong Hao‑Yang Xing Li‑Tao Yang Qian Yue Yu‑Lu Yan Kang‑Kang Zhao Jing‑Jun Zhu College of Physics Sichuan University610065 ChengduChina Department of Physics National Dong Hwa University97401 ShoufengHualienChina Department of Physics Dokuz Eylül University35160 BucaİzmirTurkey Institute of Physics Academia Sinica11529 TaipeiChina Key Laboratory of Particle and Radiation Imaging(Ministry of Education)and Department of Engineering Physics Tsinghua University100084 BeijingChina Institute of Nuclear Science and Technology Sichuan University610065 ChengduChina

Compton scattering with bound electrons contributes to a significant atomic effect in low-momentum transfer,yielding background structures in direct light Dark Matter searches as well as low-energy rare event experiments.We report the measurement of Compton scattering in low-momentum transfer by implementing a 10-g germanium detector bombarded by a^(137)Cs source with a radioactivity of 8.7 mCi and a scatter photon captured by a cylindrical NaI(Tl)detector.A fully relativistic impulse approximation combined with multi-configuration Dirac–Fock wavefunctions was evaluated,and the scattering function of Geant4 software was replaced by our calculation results.Our measurements show that the Livermore model with the modified scattering function in Geant4 is in good agreement with the experimental data.It is also revealed that atomic many-body effects significantly influence Compton scattering for low-momentum transfer(sub-keV energy transfer).

关键词： Compton scattering experiment Germanium detector Atomic many-body effects Geant4 Dark Matter

Probing Dark Matter spikes via gravitational waves of extreme-mass-ratio inspirals

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Science China(Physics,Mechanics & Astronomy) 2022年第10期65卷 45-52页

作者： Gen-Liang Li Yong Tang Yue-Liang Wu University of Chinese Academy of Sciences(UCAS) Beijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China International Center for Theoretical Physics Asia-Pacific(ICTP-AP UNESCO)UCASBeijing 100190China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100190China

The exact properties of Dark Matter remain largely unknown despite the accumulating evidence. If Dark Matter is composed of weakly interacting massive particles, it would be accreted by the black hole in the galactic center and form a dense, cuspy spike.Dynamical friction from this spike may have observable effects in a binary system. We consider extreme-mass-ratio inspiral(EMRI) binaries comprising massive black holes harbored in Dark Matter spikes and stellar mass objects in elliptic orbits. We find that the gravitational-wave waveforms in the frequency domain can be substantially modified. In particular, we show that Dark Matter can suppress the characteristic strain of a gravitational wave at low frequency but enhance it at a higher domain.These effects are more dramatic as the Dark Matter density increases. The results indicate that the signal-to-noise ratio of EMRIs can be strongly reduced near 10^(-3)-0.3 Hz but enhanced near 1.0 Hz with a higher sensitivity, which can be probed via the future space-borne gravitational-wave(GW) detectors, LISA and TAIJI. The findings will have important impacts on the detection and parameter inference of EMRIs.

关键词： Dark Matter gravitational wave black hole

Prospective study of light Dark Matter search with a newly proposed darkSHINE experiment

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Science China(Physics,Mechanics & Astronomy) 2023年第1期66卷 124-138页

作者： Jing Chen Ji-Yuan Chen Jun-Feng Chen Xiang Chen Chang-Bo Fu Jun Guo Le He Zheng-Ting He Kim Siang Khaw Jia-Lin Li Liang Li Shu Li Meng Lv Dan-Ning Liu Han-Qing Liu Kun Liu Qi-Bin Liu Yang Liu Ze-Jia Lu Cen Mo Si-Yuan Song Xiao-Long Wang Yu-Feng Wang Zhen Wang Zi-Rui Wang Wei-Hao Wu Dao Xiang Hai-Jun Yang Jun-Hua Zhang Yu-Lei Zhang Zhi-Yu Zhao Xu-Liang Zhu Chun-Xiang Zhu Yi-Fan Zhu Tsung-DaoLee Institute Shanghai Jiao Tong UniversityShanghai 201210China Institute of Nuclear and Particle Physics School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Key Laboratory for Particle Astrophysics and Cosmology(MOE) Shanghai Key Laboratory for Particle Physics and Cosmology(SKLPPC)Shanghai 200240China Center for High Energy Physics Peking UniversityBeijing 10087lChina School of Mechanical and Electronic Engineering Suzhou UniversitySuzhou 234000China School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China School of Electronics Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China R&D Center Shanghai Instituteof CeramicsChinese Academyof SciencesShanghai 20189China Key Laboratory of Nuclear Physics and lon-beam Application(MOE) Fudan UniversityShanghai 200443China Institute of Modern Physics Fudan UniversityShanghai 200443China IKey Laboratory for Laser Plasmas(MOE) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Zhangjiang Institute for Advanced Study Shanghai JiaoTong UniversityShanghai 200240.China College of Literature Scienceand the ArtsUniversity of MichiganAnn Arbor MI 48109-1040USA Deparment of Physics Swiss Federal Institnute of Technology ZurichZurich 8093Swizerland

dark photons have been well motivated as strong candidates for dark force carriers and light Dark Matter in the sub-GeV mass range.Compared with collider experiments,fixed-target experiments provide a complementary approach to searching for dark photons,particularly in the lower mass range.We have studied the physics potential of the electron-on-target experiment based on the Shanghai SHINE facility,which provides 10 MHz single electron beam at 8 GeV energy.This analysis focuses on dark photons being produced via electron and nucleon interaction and then decays to Dark Matter candidates,which escape detection as missing momentum in the detector.This experiment takes advantage of using missing momentum to enhance signal versus background separation power.In this study,signal samples as a function of dark photon mass and an inclusive background sample with 2.5 billion events are simulated with GEANT4.For better background estimates,major rare background processes have also been simulated.This paper presents the experiment and detector design,signal and background simulations,analysis strategy,and the prospective study of the experiment sensitivity.With 9×10^(14) electron-on-target events(about three years running),this experiment is expected to rule out most of the sensitive regions predicted by popular dark photon models.

关键词： Dark Matter dark photon electron-on-target experiment

Confronting cosmic ray electron and positron excesses with hybrid triplet Higgs portal Dark Matter

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Chinese Physics C 2022年第6期46卷 9-21页

作者：陈绍龙 Amit Dutta Banik 刘泽坤 Key Laboratory of Quark and Lepton Physics(MoE)and Institute of Particle Physics Central China Normal UniversityWuhan 430079China Center for High Energy Physics Peking UniversityBeijing 100871China

We perform a detailed study of scalar Dark Matter with triplet Higgs extensions of the Standard Model in order to explain the cosmic ray electron and positron excesses reported by AMS-02 and DAMPE.A detailed analysis of the AMS-02 positron excess reveals that for different orderings(normal,inverted,and quasi-degenerate)of neutrino mass,the hybrid triplet Higgs portal framework is more favored with respect to the single triplet Higgs portal for TeV scale Dark Matter.We also show that the resonant peak and continuous excess in DAMPE cosmic ray data can be well explained with the hybrid triplet Higgs portal Dark Matter when a Dark Matter sub-halo nearby is taken into account.

关键词： Dark Matter triplet Higgs neutrino mass electron and positron excesses

Search for Dark Matter production in association with the Z′ boson at the LHC in pp collisions at √s=8 TeV using Monte Carlo simulations

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Chinese Physics C 2021年第8期45卷 1-11页

作者： S.Elgammal M.A.Louka A.Y.Ellithi M.T.Hussein Centre for theoretical physics The British University in EgyptCairoEgypt Physics Department Faculty of ScienceCairo UniversityEgypt

This analysis evaluates the possibility of the search for Dark Matter(DM)particles using events with a Zf heavy gauge boson and a large missing transverse momentum at the Large Hadron Collider(LHC).We consider the muonic decay of Z'.The analyzed Monte Carlo samples were the Open simulated files produced by the Compact Muon Solenoid(CMS)collaboration for proton-proton collisions,corresponding to an integrated luminosity of the LHC run-I with 19.7 fb^(-1) at √s=8 TeV.Two scenarios,namely a simplified benchmark scenario,called dark Higgs,and the effective field theory(EFT)formalism,were used for interpretations.Limits were set on Z′,Dark Matter masses,and the cutoff scale of the EFT.

关键词： Dark Matter new heavy gauge boson Large Hadron Collider Compact Muon Solenoid

Searches for Dark Matter via charged Higgs pair production in the Inert Doublet Model at a γγ collider

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Chinese Physics C 2021年第10期45卷 16-24页

作者：杨国贺宋昴李刚张宇郭建友 School of Physics and Material Science Anhui UniversityHefei 230601China School of physics Huazhong University of Science and TechnologyHefei 230601China Institutes of Physical Science and Information Technology Anhui UniversityWuhan 430074China

The Inert Doublet Model(IDM)is one of the simplest extensions beyond the Standard Model(SM)with an extended scalar sector,which provides a scalar Dark Matter particle candidate.In this study,we investigated the double charged Higgs production at aγγcollider.By scanning the whole parameter space,we obtained the parameter points corresponding to the correct relic abundance of Dark Matter.After applying all theoretical and experimental constraints,the parameter space for the existence of Dark Matter was extremely restricted.We performed an analysis of the signal of H+H-production in the IDM and the SM background,with the optimized selection conditions chosen for the kinematic variables to maximize the signal significance.Comparing the signal with the background,we obtained the parameter points that may be detected in futureγγcollider experiments.

关键词： Dark Matter IDM large hadron collider

High energy window for probing Dark Matter with cosmic-ray antideuterium and antihelium

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Chinese Physics C 2021年第6期45卷 188-201页

作者：丁雨辰李楠魏春成周宇峰 CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASand International Centre for Theoretical Physics Asia-PacificBeijing/HangzhouChina Key Laboratory of Particle Acceleration Physics and Technology Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China

Cosmic-ray(CR)anti-nuclei are often considered important observables for indirect Dark Matter(DM)detection at low kinetic energies,below GeV per nucleon.Since the primary CR fluxes drop quickly towards high energies,the secondary anti-nuclei in CR are expected to be significantly suppressed in high energy regions(≥10 GeV per nucleon).If DM particles are heavy,the annihilation productions of DM can be highly boosted,and thus the fluxes of anti-nuclei produced by DM annihilation may exceed the secondary background at high energies,which opens a high energy window for indirect DM detection.We investigate the possibility of detecting heavy DM particles which annihilate into high energy anti-nuclei.We use the Monte Carlo generators PYTHIA,EPOS-LHC and DPMJET and the coalescence model to simulate the production of anti-nuclei,and constrain the DM annihilation cross-sections by using the AMS-02 and HAWC antiproton data and the HESS galactic center-ray data.We find that the conclusion depends on the choice of DM density profiles.For the“Cored”type profile with a DM particle mass≥10 TeV,the contributions from DM annihilation can exceed the secondary background in high energy regions,which opens the high energy window,while for the“Cuspy”type profile,the excess disappears.

关键词： Dark Matter coalescence model antideuterium antihelium