Mengmeng Wu
A5101970668- Dark Matter and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
- Cosmology and Gravitation Theories
- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Fault Detection and Control Systems
- Electrical and Bioimpedance Tomography
- Remote-Sensing Image Classification
- Computational Fluid Dynamics and Aerodynamics
- Fluid Dynamics and Turbulent Flows
- Particle Detector Development and Performance
- Flow Measurement and Analysis
- Nuclear Physics and Applications
- Image and Signal Denoising Methods
- Advanced Image Fusion Techniques
- Radiation Detection and Scintillator Technologies
- Face and Expression Recognition
- High-Energy Particle Collisions Research
- Model Reduction and Neural Networks
- Advanced Steganography and Watermarking Techniques
- Gamma-ray bursts and supernovae
- Video Coding and Compression Technologies
- Cancer, Lipids, and Metabolism
- Seismic Performance and Analysis
Nanjing University
2025
Sun Yat-sen University
2020-2024
China Institute of Atomic Energy
2023
Linyi University
2019
Northwestern Polytechnical University
2017-2019
Shandong Normal University
2018
Liaoning Normal University
2016
Northeast Petroleum University
2016
Tianjin University
2005-2007
We report a novel search for the cosmic-ray boosted dark matter using 100 tonne·day full dataset of PandaX-II detector located at China Jinping Underground Laboratory. With extra energy gained from cosmic rays, sub-GeV particles can produce visible recoil signals in detector. The diurnal modulations rate and spectrum are utilized to further enhance signal sensitivity. Our result excludes matter-nucleon elastic scattering cross section between 10^{-31} 10^{-28} cm^{2} masses 0.1 MeV/c^{2}...
We report the search results of light dark matter through its interactions with shell electrons and nuclei, using commissioning data from PandaX-4T liquid xenon detector. Low energy events are selected to have an ionization-only signal between 60 200 photoelectrons, corresponding a mean nuclear recoil 0.77 2.54 keV electronic 0.07 0.23 keV. With effective exposure 0.55 tonne$\cdot$year, we set most stringent limits within mass range 40 $\rm{MeV/c^2}$ 10 $\rm{GeV/c^2}$ for point-like...
Xe134 is a candidate isotope for neutrinoless double beta decay (0νββ) search. In addition, the two-neutrino case (2νββ) allowed by standard model of particle physics has not yet been observed. With 656-kg natural xenon in fiducial volume PandaX-4T detector, which contains 10.4% Xe134, and its initial 94.9-day exposure, we have established most stringent constraints on 2νββ 0νββ half-lives, with limits 2.8×1022 yr 3.0×1023 at 90% confidence level, respectively. The limit surpasses previously...
PandaX-4T experiment is a deep-underground dark matter direct search that employs dual-phase time projection chamber with sensitive volume containing 3.7 tonne of liquid xenon. The detector capable simultaneously collecting the primary scintillation and ionization signals, utilizing their ratio to discriminate signals from background sources such as gamma rays beta particles. signal response model plays crucial role in interpreting data obtained by PandaX-4T. It describes conversion...
We report the dark matter search results obtained using full 132 ton$\cdot$day exposure of PandaX-II experiment, including all data from March 2016 to August 2018. No significant excess events is identified above expected background. Upper limits are set on spin-independent matter-nucleon interactions. The lowest 90% confidence level exclusion cross section $2.2\times 10^{-46}$ cm$^2$ at a WIMP mass 30 GeV/$c^2$.
A bstract PandaX-4T is a ton-scale dark matter direct detection experiment using dual-phase TPC technique at the China Jinping Underground Laboratory. Various ultra-low background technologies have been developed and applied to material screening for PandaX-4T, including HPGe gamma spectroscopy, ICP-MS, NAA, radon emanation measurement system, krypton assay station, alpha system. Low materials were selected assemble detector. Surface treatment procedures investigated further suppress...
ABSTRACT The initiation and progression of clear cell renal carcinoma (ccRCC) are closely linked to significant metabolic alterations. Specifically, lipid metabolism alterations their association with the high invasiveness in ccRCC require further investigation. After conducting RNA‐sequencing (RNA‐seq), we discovered that Hydroxyacyl‐CoA Dehydrogenase Trifunctional Multienzyme Complex Subunit Beta ( HADHB ) was significantly downregulated highly invasive line. It found expression tumor...
Compared with the signature of dark matter elastic scattering off nuclei, absorption fermionic by nuclei opens up a new searching channel for light characteristic monoenergetic signal. In this Letter, we explore 95.0-day data from PandaX-4T commissioning run and report first dedicated results signal through neutral current process. No significant was found, lowest limit on matter-nucleon interaction cross section is set to be 1.5×10^{-50} cm^{2} mass 40 MeV/c^{2} 90% confidence level.
This article presents a novel approach for predicting transition locations over airfoils, which are used to activate turbulence model in Reynolds-averaged Navier-Stokes flow solver. combines Dynamic Mode Decomposition (DMD) with eN criterion. The core idea is use spatial DMD analysis extract the modes of unstable perturbations from steady flowfield and substitute local Linear Stability Theory (LST) quantify growth Tollmien–Schlichting (TS) waves. Transition assumed take place at stream-wise...
Precise measurement of two-neutrino double beta decay (DBD) half-life is an important step for the searches Majorana neutrinos with neutrinoless decay. We report DBD $^{136}$Xe using PandaX-4T dual-phase Time Projection Chamber (TPC) 3.7-tonne natural xenon and first 94.9-day physics data release. The background model in fiducial volume well constrained situ by events outer active region. With a exposure 15.5 kg-year, we establish as $2.27 \pm 0.03 (stat.)\pm 0.10 (syst.)\times 10^{21}$...
We propose a major upgrade to the existing PandaX-4T experiment in China Jinping Underground Laboratory. The new experiment, PandaX-xT, will be multi-ten-tonne liquid xenon, ultra-low background, and general-purpose observatory. full-scaled PandaX-xT contains 43-tonne xenon active target. Such an significantly advance our fundamental understanding of particle physics astrophysics. sensitivity dark matter direct detection improved by nearly two orders magnitude compared current best limits,...
Abstract We present a systematic determination of the responses PandaX-II, dual phase xenon time projection chamber detector, to low energy recoils. The electron recoil (ER) and nuclear (NR) are calibrated, respectively, with injected tritiated methane or 220 Rn source, 241 Am-Be neutron in an range from 1-25 keV 4-80 (NR), under two drift fields, 400 317 V/cm. An empirical model is used fit light yield charge for both types best models can describe calibration data significantly....
We present the constraints on axial-vector and pseudo-scalar mediated WIMP-nucleus interactions from PandaX-4T experiment, using data set corresponding to a total exposure of 0.63~tonne$\cdot$year. No significant signal excess is observed, most stringent upper limits date spin-dependent WIMP-neutron scattering cross section are at 90\% confidence level with minimum 5.8$\times 10^{-42}$\si{\cm^{2}} for WIMP mass 40~\si{\GeV/}$c^2$. Exclusion simplified models also derived.
In the probe limit, we investigate nonlinear electrodynamical effects of both exponential form and logarithmic on holographic paramagnetism–ferromagnetism phase transition in background a Schwarzschild-AdS black hole spacetime. Moreover, by comparing electrodynamics with Born–Infeld which has been presented Ref. [55], find that higher correction makes critical temperature smaller magnetic moment harder case without external field. Furthermore, increase parameter b will result extending...
We report a search for light dark matter produced through the cascading decay of η mesons, which are created as result inelastic collisions between cosmic rays and Earth's atmosphere. introduce new general framework, publicly accessible, designed to address boosted specifically, with full dedicated simulation including both elastic quasielastic processes Earth attenuation effect on particles arriving at detector is performed. In PandaX-4T commissioning data 0.63 tonne⋅year exposure, no...
We presented a RAO hypothesis detector by modeling Cauchy distribution for the Nonsubsampled Contourlet Transform (NSCT) subband coefficients in field of additive spread spectrum image watermarking. Firstly, NSCT were modeled following distributions, and Fit Goodness shows that fits more accurately than Generalized Gaussian Distribution (GGD) commonly used. Secondly, blind test watermark was derived domain, which does not need knowledge embedding strength at receiving end. Finally, compared...
The PandaX-II experiment employed a 580kg liquid xenon detector to search for the interactions between dark matter particles and target atoms. accidental coincidences of isolated signals result in dangerous background which mimic signature matter. We performed detailed study on coincidence PandaX-II, including possible origin signals, level corresponding suppression method. With boosted-decision-tree algorithm, is reduced by 70% signal region, thus sensitivity at improved.
In the two-component Majorana dark matter model, one particle can scatter off target nuclei, and turn into a slightly heavier component. framework of simplified model with vector boson mediator, both tree-level loop-level processes contribute to signal in direct detection experiment. this paper, we report search results for such from PandaX-II experiment, using total data full 100.7 tonne$\cdot$day exposure. No significant excess is observed, so strong constraints on combined parameter space...
Flow regime is one of the fundamental parameters with important engineering significance in two-phase flow systems, and has always been an aspect research. In this paper, support vector machine (SVM) method statistics theories was adopted to analyze measured data electrical resistance tomography (ERT) system so that identification gas/liquid horizontal pipe carried out. The analysis result experiment indicates can obtain inspiring result.
Neutron-induced nuclear recoil background is critical to the dark matter searches in PandaX-4T liquid xenon experiment. This paper studies feature of neutron and evaluates their contribution single scattering events through three methods. The first method fully Monte Carlo simulation based. last two are data-driven methods that also use multiple signals high energy data, respectively. In commissioning data with an exposure 0.63 tonne-year, all these give a consistent result there...
Gas/liquid two-phase flow system is a complex, nonlinear and dynamic system, therefore difficult to measure. Basing on the application of electrical resistance tomography (ERT) in gas/liquid vertical pipe, wavelets transform used analyses measured data from ERT system. Furthermore, according multi-resolution analysis (MRA), feature vector multiple scales wavelet energy that can express essential information constructed. At last, support machine (SVM) method statistics theories adopted...