Showing papers by "Deqing Fang published in 2019"
TL;DR: In this article, a simulation study of the expected background in PandaX-4T is presented, where the authors show that in a 2.8-ton fiducial mass and the signal region between 1-10 keV electron equivalent energy, the total electron recoil background is found to be$\\rm~4.9\\times~10-5}kg^{-1}d^{- 1}keV
Abstract: The PandaX-4T experiment, a 4-ton scale dark matter direct detection experiment, is being planned at the China Jinping Underground Laboratory. In this paper we present a simulation study of the expected background in this experiment. In a 2.8-ton fiducial mass and the signal region between 1-10 keV electron equivalent energy, the total electron recoil background is found to be$\\rm~4.9\\times~10^{-5}kg^{-1}d^{-1}keV^{-1}$. The nuclear recoil background in the same region is $\\rm~2.8\\times~10^{-7}kg^{-1}d^{-1}keV^{-1}$. With an exposure of 5.6 ton-years, the sensitivity of PandaX-4T could reach a minimum spin-independent dark matter-nucleon cross section of $\\rm~6\\times~10^{-48}cm^2$ at a dark matter mass of 40 GeV/$c^2$.
176 citations
Shanghai Jiao Tong University1, Xinjiang University2, Chinese Academy of Sciences3, Shandong University4, Nankai University5, Peking University6, University of Maryland, College Park7, University of Shanghai for Science and Technology8, University of California, Berkeley9, Lawrence Berkeley National Laboratory10
TL;DR: In this article, the authors present PandaX-II constraints on candidate WIMP-nucleon effective interactions involving the nucleon or WimP spin, including, in addition, standard axial spin-dependent scattering, various couplings among vector and axial currents, magnetic and electric dipole moments, and tensor interactions.
61 citations
TL;DR: In this paper, the Neutrino-less Double Beta Decay (NLDBD) search results from PandaX-II dual-phase liquid xenon time projection chamber were reported.
Abstract: We report the Neutrino-less Double Beta Decay (NLDBD) search results from PandaX-II dual-phase liquid xenon time projection chamber. The total live time used in this analysis is 403.1 days from June 2016 to August 2018. With NLDBD-optimized event selection criteria, we obtain a fiducial mass of 219 kg of natural xenon. The accumulated xenon exposure is 242 kg·yr, or equivalently 22.2 kg·yr of 136Xe exposure. At the region around 136Xe decay Q-value of 2458 keV, the energy resolution of PandaX-II is 4.2%. We find no evidence of NLDBD in PandaX-II and establish a lower limit for decay half-life of 2.1 \begin{document}$ \times 10^{23} $\end{document} yr at the 90% confidence level, which corresponds to an effective Majorana neutrino mass \begin{document}$m_{\beta \beta} eV. This is the first NLDBD result reported from a dual-phase xenon experiment.
22 citations
TL;DR: In this paper, a method for calibrating the relationship between particle energy and track diameter in a Columbia Resin #39 (CR-39) detector (TasTrak®) using 3-8-MeV protons, 6-30-meV carbon ions, and 1-5-MEV alpha particles was presented.
19 citations
TL;DR: In this paper, a finite-size scaling effect on nuclear liquid-gas phase transition probes was investigated by studying the de-excitation processes of six thermal sources of different sizes with the same initial density.
Abstract: Based on the isospin-dependent quantum molecular dynamics model, finite-size scaling effects on nuclear liquid-gas phase transition probes are investigated by studying the de-excitation processes of six thermal sources of different sizes with the same initial density and similar $N/Z$. Using several probes including the total multiplicity derivative ($d{M}_{\text{tot}}/dT$), second moment parameter (${M}_{2}$), intermediate mass fragment (IMF) multiplicity (${N}_{\text{IMF}}$), Fisher's power-law exponent ($\ensuremath{\tau}$), and Ma's nuclear Zipf's law exponent ($\ensuremath{\xi}$), the relationship between the phase transition temperature and the source size has been established. It is observed that the phase transition temperatures obtained from the IMF multiplicity, Fisher's exponent, and Ma's nuclear Zipf's law exponent have a strong correlation with the source size. Moreover, by employing the finite-size scaling law, the critical temperature ${T}_{c}$ and the critical exponent $\ensuremath{
u}$ were obtained for infinite nuclear matter.
17 citations
TL;DR: In this paper, the deuteron beam is delivered from a 4-MeV electrostatic accelerator and bombarded on a thick carbon target, and the neutrons are detected at 0.6-3 MeV, 1.4 MeV and 2.7 MeV.
12 citations
TL;DR: The neutrinoless double beta decay results of CUORE from examining a total TeO 2 exposure of 86.3 kg yr, characterized by an effective energy resolution of 7.7 keV FWHM and a background in the region of interest of 0.014 counts / ( keV kg yr ).
Abstract: The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay that has been able to reach the 1-ton scale. The detector consists of an array of 988 TeO 2 crystals arranged in a cylindrical compact structure of 19 towers, each of them made of 52 crystals. The construction of the experiment was completed in August 2016 and the data taking started in spring 2017 after a period of commissioning and tests. In this work we present the neutrinoless double beta decay results of CUORE from examining a total TeO 2 exposure of 86.3 kg yr , characterized by an effective energy resolution of 7.7 keV FWHM and a background in the region of interest of 0.014 counts / ( keV kg yr ) . In this physics run, CUORE placed a lower limit on the decay half-life of neutrinoless double beta decay of 130 Te > 1.3 · 10 25 yr (90% C.L.). Moreover, an analysis of the background of the experiment is presented as well as the measurement of the 130 Te 2 ν β β decay with a resulting half-life of T 1 / 2 2 ν = [ 7.9 ± 0.1 ( stat . ) ± 0.2 ( syst . ) ] × 10 20 yr which is the most precise measurement of the half-life and compatible with previous results.
6 citations
Posted Content•
TL;DR: In this article, the authors presented an improved evaluation of the neutron background in the PandaX-II dark matter experiment by a novel approach, instead of fully relying on the Monte Carlo simulation, the overall neutron background is determined from the neutron-induced high energy signals in the data.
Abstract: In dark matter direct detection experiments, neutron is a serious source of background, which can mimic the dark matter-nucleus scattering signals. In this paper, we present an improved evaluation of the neutron background in the PandaX-II dark matter experiment by a novel approach. Instead of fully relying on the Monte Carlo simulation, the overall neutron background is determined from the neutron-induced high energy signals in the data. In addition, the probability of producing a dark-matter-like background per neutron is evaluated with a complete Monte Carlo generator, where the correlated emission of neutron(s) and $\gamma$(s) in the ($\alpha$, n) reactions and spontaneous fissions is taken into consideration. With this method, the neutron backgrounds in the Run 9 (26-ton-day) and Run 10 (28-ton-day) data sets of PandaX-II are estimated to be 0.66$\pm$0.24 and 0.47$\pm$0.25 events, respectively.
3 citations
TL;DR: In this paper, the Neutrino-less Double Beta Decay (NLDBD) search results from PandaX-II dual-phase liquid xenon time projection chamber were reported.
Abstract: We report the Neutrino-less Double Beta Decay (NLDBD) search results from PandaX-II dual-phase liquid xenon time projection chamber. The total live time used in this analysis is 403.1 days from June 2016 to August 2018. With NLDBD-optimized event selection criteria, we obtain a fiducial mass of 219 kg of natural xenon. The accumulated xenon exposure is 242 kg$\cdot$yr, or equivalently 22.2 kg$\cdot$yr of $^{136}$Xe exposure. At the region around $^{136}$Xe decay Q-value of 2458 keV, the energy resolution of PandaX-II is 4.2%. We find no evidence of NLDBD in PandaX-II and establish a lower limit for decay half-life of 2.4 $ \times 10^{23} $ yr at the 90% confidence level, which corresponds to an effective Majorana neutrino mass $m_{\beta \beta} < (1.3 - 3.5)$ eV. This is the first NLDBD result reported from a dual-phase xenon experiment.