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Solar neutrino background in high-pressure gaseous ^(82)SeF_(6) TPC neutrinoless double beta decay experiments
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作者 王杰妙 汪虎林 张冬亮 《Chinese Physics C》 SCIE CAS CSCD 2024年第4期20-33,共14页
In this study,the possibility of observing a solar neutrino background in a future neutrinoless double beta decay experiment using a high-pressure gaseous ^(82)SeF_(6) TPC is investigated.Various contributions are sim... In this study,the possibility of observing a solar neutrino background in a future neutrinoless double beta decay experiment using a high-pressure gaseous ^(82)SeF_(6) TPC is investigated.Various contributions are simulated,and possible features that could be used for event classification are discussed;two types of backgrounds are identified.The rate of multi-site background events is approximately 0.63 events/(ton·yr)in a 30 keV ROI window.This background could be effectively reduced to less than 0.0001 events/(ton·yr)(95%C.L.)while maintaining a high signal efficiency of 93%by applying a selection based on the number of clusters and energy of the leading cluster.The rate of the single-electron background events is approximately 0.01 events/(ton·yr)in the ROI.Assuming a reduction factor of 10 for the single-electron background events obtained via the algorithms developed for radioactive background rejection,the total background induced by the solar neutrino would be 0.001 events/(ton·yr),which is sufficiently small for conducting ton-level experiments. 展开更多
关键词 neutrinoless double beta decay SeF6 high-pressure TPC solar neutrino
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Searching for ^(76)Ge neutrinoless double beta decay with the CDEX-1B experiment
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作者 Bing-Tao Zhang Jun-Zheng Wang +82 位作者 Li-Tao Yang Qian Yue Ke-Jun Kang Yuan-Jing Li Hai-Peng An C.Greeshma Jian-Ping Chang Yun-Huan Chen Jian-Ping Cheng Wen-Han Dai Zhi Deng Chang-Hao Fang Xin-Ping Geng Hui Gong Qiu-Ju Guo Xu-Yuan Guo Li He Sheng-Ming He Jin-Wei Hu Han-Xiong Huang Tu-Chen Huang Hai-Tao Jia Xi Jiang S.Karmakar Hao-Bin Li Jian-Min Li Jin Li Qian-Yun Li Ren-Ming-Jie Li Xue-Qian Li Yu-Lan Li Yi-Fan Liang Bin Liao Fong-Kay Lin Shin-Ted Lin Jia-Xuan Liu Shu-Kui Liu Yan-Dong Liu Yu Liu Yuan-Yuan Liu Zhong-Zhi Liu Hao Ma Yu-Cai Mao Qi-Yuan Nie Jin-Hua Ning Hui Pan Ning-Chun Qi Jie Ren Xi-Chao Ruan Ze She Manoj Kumar Singh Tian-Xi Sun Chang-Jian Tang Wei-You Tang Yang Tian Guang-Fu Wang Li Wang Qing Wang Yu-Feng Wang Yun-Xiang Wang Henry-Tsz-King Wong Shi-Yong Wu Yu-Cheng Wu Hao-Yang Xing Rui Xu Yin Xu Tao Xue Yu-Lu Yan Nan Yi Chun-Xu Yu Hai-Jun Yu Jian-Feng Yue Ming Zeng Zhi Zeng Feng-Shou Zhang Lei Zhang Zhen-Hua Zhang Zhen-Yu Zhang Kang-Kang Zhao Ming-Gang Zhao Ji-Fang Zhou Zu-Ying Zhou Jing-Jun Zhou 《Chinese Physics C》 SCIE CAS CSCD 2024年第10期11-22,共12页
We operated a p-type point contact high purity germanium(PPCGe)detector(CDEX-1B,1.008 kg)in the China Jinping Underground Laboratory(CJPL)for 500.3 days to search for neutrinoless double beta(0νββ)decay of ^(76)Ge.... We operated a p-type point contact high purity germanium(PPCGe)detector(CDEX-1B,1.008 kg)in the China Jinping Underground Laboratory(CJPL)for 500.3 days to search for neutrinoless double beta(0νββ)decay of ^(76)Ge.A total of 504.3 kg⋅day effective exposure data was accumulated.The anti-coincidence and the multi/single-site event(MSE/SSE)discrimination methods were used to suppress the background in the energy region of interest(ROI,1989–2089 keV for this work)with a factor of 23.A background level of 0.33 counts/(keV⋅kg⋅yr)was realized.The lower limit on the half life of^(76)Ge 0νββdecay was constrained as T_(1/2)^(0ν)>1.0×10^(23)yr(90%C.L.),corresponding to the upper limits on the effective Majorana neutrino mass:<mββ><3.2–7.5 eV. 展开更多
关键词 neutrinoless double beta decay CDEX point-contact germanium detector ^(76)Ge
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Search for two-neutrino double-beta decay of^(136)Xe to the 0^(+)_(1)excited state of 136Ba with the complete EXO-200 dataset
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作者 S.Al Kharusi G.Anton +104 位作者 I.Badhrees P.S.Barbeau D.Beck V.Belov T.Bhatta M.Breidenbach T.Brunner G.F.Cao W.R.Cen C.Chambers B.Cleveland M.Coon A.Craycraft T.Daniels L.Darroch S.J.Daugherty J.Davis S.Delaquis A.Der Mesrobian-Kabakian R.DeVoe J.Dilling A.Dolgolenko M.J.Dolinski J.Echevers W.Fairbank Jr. D.Fairbank J.Farine S.Feyzbakhsh P.Fierlinger Y.S.Fu D.Fudenberg P.Gautam R.Gornea G.Gratta C.Hall E.V.Hansen J.Hoessl P.Hufschmidt M.Hughes A.Iverson A.Jamil C.Jessiman M.J.Jewell A.Johnson A.Karelin L.J.Kaufman T.Koffas R.Krücken A.Kuchenkov K.S.Kumar Y.Lan A.Larson B.G.Lenardo D.S.Leonard G.S.Li S.Li Z.Li C.Licciardi Y.H.Lin R.MacLellan T.McElroy T.Michel B.Mong D.C.Moore K.Murray O.Njoya O.Nusair A.Odian I.Ostrovskiy A.Perna A.Piepke A.Pocar F.Retière A.L.Robinson P.C.Rowson J.Runge S.Schmidt D.Sinclair K.Skarpaas A.K.Soma V.Stekhanov M.Tarka S.Thibado J.Todd T.Tolba T.I.Totev R.Tsang B.Veenstra V.Veeraraghavan P.Vogel J.-L.Vuilleumier M.Wagenpfeil J.Watkins M.Weber L.J.Wen U.Wichoski G.Wrede S.X.Wu Q.Xia D.R.Yahne L.Yang Y.-R.Yen O.Ya.Zeldovich T.Ziegler 《Chinese Physics C》 SCIE CAS CSCD 2023年第10期1-9,共9页
A new search for two-neutrino double-beta(2νββ)decay of^(136)Xe to the 0+1 excited state of 136Ba is performed with the full EXO-200 dataset.A deep learning-based convolutional neural network is used to discriminat... A new search for two-neutrino double-beta(2νββ)decay of^(136)Xe to the 0+1 excited state of 136Ba is performed with the full EXO-200 dataset.A deep learning-based convolutional neural network is used to discriminate signal from background events.Signal detection efficiency is increased relative to previous searches by EXO-200 by more than a factor of two.With the addition of the Phase II dataset taken with an upgraded detector,the median 90%confidence level half-life sensitivity of 2νββdecay to the 0+1 state of 136Ba is 2.9×10^(24)yr using a total^(136)Xe exposure of 234.1 kg yr.No statistically significant evidence for 2νββdecay to the 0^(+)_(1)state is observed,leading to a lower limit of T2ν1/2(0^(+)→0^(+)_(1))>1.4×10^(24)yr at 90%confidence level,improved by 70%relative to the current world's best constraint. 展开更多
关键词 EXO-200 experiment neutrinoless double beta decay excited state
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NνDEx-100 conceptual design report
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作者 Xi-Guang Cao Yan-Long Chang +35 位作者 Kai Chen Emilio Ciuffoli Li-Min Duan Dong-Liang Fang Chao-Song Gao Surja K.Ghorui Peng-Chong Hu Qiang Hu Si-Yuan Huang Ze-Yu Huang Lei Lang Yu-Lan Li Zhi-Jie Li Tian-Yu Liang Jun Liu Chen-Gui Lu Fa-Tai Mai Yuan Mei Hao Qiu Xiang-Ming Sun Xiao-Xing Tang Hu-Lin Wang Qian-Ming Wang Le Xiao Mu-Yun Xiao Jian-Yu Xin Nu Xu Peng Yang Yi-Chen Yang Zhen Yang Zong-Yang Yu Dong-Liang Zhang Jun-Wei Zhang Cheng-Xin Zhao Dou Zhu NνDEx-100 collaboration 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第1期18-33,共16页
Observing nuclear neutrinoless double beta (0vββ) decay would be a revolutionary result in particle physics.Observing such a decay would prove that the neutrinos are their own antiparticles,help to study the absolut... Observing nuclear neutrinoless double beta (0vββ) decay would be a revolutionary result in particle physics.Observing such a decay would prove that the neutrinos are their own antiparticles,help to study the absolute mass of neutrinos,explore the origin of their mass,and may explain the matter-antimatter asymmetry in our universe by lepton number violation.We propose developing a time projection chamber (TPC) using high-pressure ^(82)SeF_(6) gas and Topmetal silicon sensors for readout in the China Jinping Underground Laboratory (CJPL) to search for neutrinoless double beta decay of82Se,called the NvDEx experiment.Besides being located at CJPL with the world’s thickest rock shielding,NvDEx combines the advantages of the high Qββ(2.996 MeV) of82Se and the TPC’s ability to distinguish signal and background events using their different topological characteristics.This makes NvDEx unique,with great potential for low-background and high-sensitivity 0 vββsearches.NvDEx-100,a NvDEx experiment phase with 100 kg of SeF_(6)gas,is being built,with plans to complete installation at CJPL by 2025.This report introduces 0 vββ physics,the NvDEx concept and its advantages,and the schematic design of NvDEx-100,its subsystems,and background and sensitivity estimation. 展开更多
关键词 Neutrinoless double beta decay Time projection chamber ^(82)SeF_(6) China Jinping Underground Laboratory
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First results on ^(76)Ge neutrinoless double beta decay from CDEX-1 experiment 被引量:7
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作者 Li Wang Qian Yue +66 位作者 KeJun Kang JianPing Cheng YuanJing Li TszKing Henry Wong ShinTed Lin JianPing Chang JingHan Chen QingHao Chen YunHua Chen Zhi Deng Qiang Du Hui Gong Li He QingJu He JinWei Hu HanXiong Huang TengRui Huang LiPing Jia Hao Jiang HauBin Li Hong Li JianMin Li Jin Li Jun Li Xia Li XueQian Li YuLan Li FongKay Lin ShuKui Liu Hao Ma JingLu Ma XingYu Pan Jie Ren XiChao Ruan ManBin Shen Vivek Sharma Lakhwinder Singh Manoj Kumar Singh Manoj Kumar Singh Arun Kumar Soma ChangJian Tang WeiYou Tang ChaoHsiung Tseng JiMin Wang Qing Wang ShiYong Wu YuCheng Wu HaoYang Xing Yin Xu Tao Xue LiTao Yang SongWei Yang Nan Yi ChunXu Yu HaiJun Yu WeiHe Zeng XiongHui Zeng Zhi Zeng Lan Zhang YunHua Zhang MingGang Zhao Wei Zhao JiFang Zhou ZuYing Zhou JingJun Zhu WeiBin Zhu ZhongHua Zhu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2017年第7期53-59,共7页
We report the first results on 76Ge neutrinoless double beta decay from stage one of the China dark-matter experiment (CDEX). A p-type point-contact high-purity germanium detector with a mass of 994g has been instal... We report the first results on 76Ge neutrinoless double beta decay from stage one of the China dark-matter experiment (CDEX). A p-type point-contact high-purity germanium detector with a mass of 994g has been installed to detect neutrinoless double beta decay events, as well as to directly detect dark matter particles. An exposure of 304kgd has been analyzed over a wide spectral band from 500keV to 3MeV. The average event rate obtained was about 0.012 counts per keV per kg per day over the 2.039MeV energy range. The half-life of76Ge neutrinoless double beta decay derived based on this result is 70v2〉6.4× 1022 yr (90%C.L.). An upper limit on the effective Majorana-neutrino mass of 5.0eV has been achieved. 展开更多
关键词 neutrinoless double beta decay CDEX point-contact germanium detector 76Ge isotope
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Study of CdMoO4 crystal for a neutrinoless double beta decay experiment with ^116Cd and ^100Mo nuclides 被引量:1
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作者 薛明萱 张云龙 +2 位作者 彭海平 许咨宗 汪晓莲 《Chinese Physics C》 SCIE CAS CSCD 2017年第4期149-154,共6页
The scintillation properties of a CdMoO4 crystal have been investigated experimentally.The fluorescence yields and decay times measured from 22 K to 300 K demonstrate that CdMoO4 crystal is a good candidate for an abs... The scintillation properties of a CdMoO4 crystal have been investigated experimentally.The fluorescence yields and decay times measured from 22 K to 300 K demonstrate that CdMoO4 crystal is a good candidate for an absorber for a bolometer readout,for both heat and scintillation signals.The results from Monte Carlo studies,taking the backgrounds from 2ν2β of^100 42Mo ^116 48Cd) and internal trace nuclides ^214Bi and ^208Tl into account,show that the expected sensitivity of a CdMoO4 bolometer for neutrinoless double beta decay experiments with an exposure of 100kg·years is one order of magnitude higher than those of the current sets of the limT1/2^0νββ of ^100 42Mo and ^116 48Cd. 展开更多
关键词 neutrinoless double beta decay CdMo04 crystal BOLOMETER radioactive contamination scintillation properties
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Panda X-III: Searching for neutrinoless double beta decay with high pressure ^(136)Xe gas time projection chambers 被引量:4
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作者 Xun Chen Chang Bo Fu +67 位作者 Javier Galan Karl Giboni Franco Giuliani Ling Hui Gu Ke Han Xiang Dong Ji Heng Lin Jiang Lai Liu Kai Xiang Ni Hiroki Kusano Xiang Xiang Ren Shao Bo Wang Yong Yang Dan Zhang Tao Zhang Li Zhao Xiang Ming Sun Shou Yang Hu Si Yu Jian Xing Long Li Xiao Mei Li Hao Liang Huan Qiao Zhang Ming Rui Zhao Jing Zhou Ya Jun Mao Hao Qiao Si Guang Wang Ying Yuan Meng Wang Amir N.Khan Neill Raper Jian Tang Wei Wang Jia Ning Dong Chang Qing Feng Cheng Li Jian Bei Liu Shu Bin Liu Xiao Lian Wang Dan Yang Zhu Juan F.Castel Susana Cebri'an Theopisti Dafni Javier G.Garza Igor G.Irastorza Francisco J.Iguaz Gloria Luz ′on Hector Mirallas Stephan Aune Eric Berthoumieux Yann Bedfer Denis Calvet Nicole d'Hose Alain Delbart Maria Diakaki Esther Ferrer-Ribas Andrea Ferrero Fabienne Kunne Damien Neyret Thomas Papaevangelou Franck Sabatie Maxence Vanderbroucke AnDi Tan Wick Haxton Yuan Mei Chinorat Kobdaj Yu-Peng Yan 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2017年第6期8-47,共40页
Searching for the neutrinoless double beta decay(NLDBD)is now regarded as the topmost promising technique to explore the nature of neutrinos after the discovery of neutrino masses in oscillation experiments.Panda X-II... Searching for the neutrinoless double beta decay(NLDBD)is now regarded as the topmost promising technique to explore the nature of neutrinos after the discovery of neutrino masses in oscillation experiments.Panda X-III(particle and astrophysical xenon experiment III)will search for the NLDBD of136Xe at the China Jin Ping Underground Laboratory(CJPL).In the first phase of the experiment,a high pressure gas Time Projection Chamber(TPC)will contain 200 kg,90%136Xe enriched gas operated at10 bar.Fine pitch micro-pattern gas detector(Microbulk Micromegas)will be used at both ends of the TPC for the charge readout with a cathode in the middle.Charge signals can be used to reconstruct the electron tracks of the NLDBD events and provide good energy and spatial resolution.The detector will be immersed in a large water tank to ensure~5 m of water shielding in all directions.The second phase,a ton-scale experiment,will consist of five TPCs in the same water tank,with improved energy resolution and better control over backgrounds. 展开更多
关键词 neutrinoless double beta decay lepton number violation underground experiment TPC Micromegas
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Enhanced search sensitivity to the double beta decay of ^(136)Xe to excited states with topological signatures
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作者 Chen Xie Kaixiang Ni +1 位作者 Ke Han Shaobo Wang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2021年第6期41-50,共10页
The double beta decay of ^(136)Xe to excited states of 136Ba(DBD-ES)has not yet been discovered experimentally.The experimental signature of such decays,one or two gamma rays following the beta signals,can be identifi... The double beta decay of ^(136)Xe to excited states of 136Ba(DBD-ES)has not yet been discovered experimentally.The experimental signature of such decays,one or two gamma rays following the beta signals,can be identified more effectively in a gaseous detector with the help of topological signatures.We have investigated key parameters of particle trajectories of DBD-ES with Monte Carlo simulation data of the proposed PandaX-III detector as an example.The background rates can be reduced by about one order of magnitude while keeping more than half of signals with topological analysis.The estimated half-life sensitivity of DBD-ES can be improved by 1.8 times to 4.1×10^(23) year(90%C.L.).Similarly,the half-life sensitivity of neutrinoless double beta decay of ^(136)Xe to excited states of 136Ba can be improved by a factor of 4.8 with topological signatures. 展开更多
关键词 NEUTRINO double beta decay topological signatures background suppression
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Hiding neutrinoless double beta decay in the minimal seesaw model with the TM1 orμ-τreflection symmetry
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作者 Zhen-Hua Zhao Yan-Bin Sun Ying-Ke Lei 《Communications in Theoretical Physics》 SCIE CAS CSCD 2022年第11期98-105,共8页
In Asaka et al(2021 Phys.Rev.D 103,015014),Asaka,Ishida and Tanaka put forward an interesting possibility that the neutrinoless double beta decay can be hidden in the minimal seesaw model with the two right-handed neu... In Asaka et al(2021 Phys.Rev.D 103,015014),Asaka,Ishida and Tanaka put forward an interesting possibility that the neutrinoless double beta decay can be hidden in the minimal seesaw model with the two right-handed neutrinos having a hierarchical mass structure:the lighter one is lighter enough than the typical Fermi-momentum scale of nuclei while the heavier one is sufficiently heavy to decouple from the neutrinoless double beta decay.Then,in the basis where the mass matrices of the charged leptons and right-handed neutrinos are diagonal,for some particular texture of the Dirac neutrino mass matrix M_(D),the neutrinoless double beta decay can be hidden.In this paper,on top of this specified model,we study the interesting scenario that M_(D)further obeys the TM1 symmetry orμ-τreflection symmetry which are well motivated by the experimental results for the neutrino mixing parameters. 展开更多
关键词 neutrino mass neutrinoless double beta decay minimal seesaw model
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Neutrino Properties Probed by Lepton Number Violating Processes
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作者 Sabin Stoica 《Open Journal of Microphysics》 2013年第3期5-9,共5页
Study of neutrino properties is nowadays one of the most active domains of research in physics. On the one hand, fundamental properties of the neutrinos like their absolute mass, their character (are they Dirac or Maj... Study of neutrino properties is nowadays one of the most active domains of research in physics. On the one hand, fundamental properties of the neutrinos like their absolute mass, their character (are they Dirac or Majorana particles?) and the number of neutrino flavors, are still unknown. On the other hand, the knowledge of these properties are of great importance since the neutrinos are very abundant in nature and play a key role in nuclear and particle physics, astrophysics and cosmology. In addition, the results of the neutrino oscillation experiments have convincingly showed that neutrinos have mass and mix, in contradiction to the initial assumptions of the Standard Model. In this context there is an increased interest in the study of the Lepton Number Violating (LNV) processes, since they are capable to decide on the above mentioned neutrino properties. Since recently, the neutrinoless double beta (0nββ) decay was considered the only process able to distinguish between Dirac or Majorana neutrinos and to give a hint on the absolute mass of the electron neutrino. At present, the increased luminosity of the LHC experiments at CERN makes it feasable the search for LNV processes at LHC as well. Besides the neutrino character, these studies can also shed light on the existence of other types of neutrinos (the sterile neutrinos), than the three known ones. In this paper, I make a brief review on our present knowledge about the neutrino properties and on the way they can be probed by LNV processes at low- and high-energies. Particularly, I refer to the 0nββ decay process and to the first attempts of searching of LNV processes in hadron collider experiments, particularly in LHC experiments at CERN-Geneva. 展开更多
关键词 NEUTRINOS NEUTRINO OSCILLATIONS double beta decay NEUTRINO Mass LEPTON Number VIOLATION
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What can we learn from recent 2νββexperiments?
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作者 房栋梁 《Chinese Physics C》 SCIE CAS CSCD 2024年第3期93-103,共11页
Recent measurements of the two neutrino double beta decay high precision electron spectra,combined with charge exchange orβ-decay experimental data,have revealed severe constraints across current nuclear many body ca... Recent measurements of the two neutrino double beta decay high precision electron spectra,combined with charge exchange orβ-decay experimental data,have revealed severe constraints across current nuclear many body calculations.Our calculations show that the quasi-particle random phase approximation(QRPA)approach can adequately reproduce the measured spectra for the two open shell nuclei,^(82)Se and ^(100)Mo.For the closed shell nucleus ^(136)Xe,QRPA can also reproduce the spectra with proper treatments.Considering the high-lying state reduction,we also find that the nuclear shell model can also adequately reproduce the spectra and Gamow-Teller transition strength under a unique quenched axial-vector coupling constant gA.For ^(136)Xe,we find that flipping the sign for the decay strength causes the spectra to go beyond the so-called high-lying state dominance hypothesis.These results call for future high precision measurements of charge-exchange reactions. 展开更多
关键词 nuclear stucture double beta decay electron spectra
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Searching for neutrino-less nouble neta necay of 136Xe with PandaX-Ⅱ liquid xenon detector 被引量:2
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作者 Kaixiang Ni Yihui Lai +60 位作者 Abdusalam Abdukerim Wei Chen Xun Chen Yunhua Chen Xiangyi Cui Yingjie Fan Deqing Fang Changbo Fu Lisheng Geng Karl Giboni Franco Giuliani Linhui Gu Xuyuan Guo Ke Han Changda He Di Huang Yan Huang Yanlin Huang Zhou Huang Peng Ji Xiangdong Ji Yonglin Ju Kun Liang Huaxuan Liu Jianglai Liu Wenbo Ma Yugang Ma Yajun Mao Yue Meng Parinya Namwongsa Jinhua Ning Xuyang Ning Xiangxiang Ren Changsong Shang Lin Si Andi Tan Anqing Wang Hongwei Wang Meng Wang Qiuhong Wang Siguang Wang Xiuli Wang Zhou Wang Mengmeng Wu Shiyong Wu Jingkai Xia Mengjiao Xiao Pengwei Xie Binbin Yan Jijun Yang Yong Yang Chunxu Yu Jumin Yuan Dan Zhang Hongguang Zhang Tao Zhang Li Zhao Qibin Zheng Jifang Zhou Ning Zhou Xiaopeng Zhou 《Chinese Physics C》 SCIE CAS CSCD 2019年第11期1-10,共10页
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 August2018... 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 August2018.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-Ⅱand establish a lower limit for decay half-life of 2.1×1023yr at the 90% confidence level,which corresponds to an effective Majorana neutrino mass mββ <(1.4-3.7) eV.This is the first NLDBD result reported from a dual-phase xenon experiment. 展开更多
关键词 neutrino-less double beta decay DARK matter underground physics liquid XENON DETECTOR
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Physics potential of searching for 0νββ decays in JUNO 被引量:2
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作者 赵洁 温良剑 +1 位作者 王贻芳 曹俊 《Chinese Physics C》 SCIE CAS CSCD 2017年第5期6-15,共10页
In the past few decades,numerous searches have been made for the neutrinoless double-beta decay(0νββ) process,aiming to establish whether neutrinos are their own antiparticles(Majorana neutrinos),but no 0νββ... In the past few decades,numerous searches have been made for the neutrinoless double-beta decay(0νββ) process,aiming to establish whether neutrinos are their own antiparticles(Majorana neutrinos),but no 0νββdecay signal has yet been observed.A number of new experiments are proposed but they ultimately suffer from a common problem: the sensitivity may not increase indefinitely with the target mass.We have performed a detailed analysis of the physics potential by using the Jiangmen Underground Neutrino Observatory(JUNO) to improve the sensitivity to 0νββ up to a few me V,a major step forward with respect to the experiments currently being planned.JUNO is a 20 kton low-background liquid scintillator(LS) detector with 3%/(E(MeV))1/2 energy resolution,now under construction.It is feasible to build a balloon filled with enriched xenon gas(with136Xe up to 80%) dissolved in LS,inserted into the central region of the JUNO LS.The energy resolution is 1.9% at the Q-value of 136Xe 0νββ decay.Ultra-low background is the key for 0νββ decay searches.Detailed studies of background rates from intrinsic 2νββ and 8B solar neutrinos,natural radioactivity,and cosmogenic radionuclides(including light isotopes and 137Xe) were performed and several muon veto schemes were developed.We find that JUNO has the potential to reach a sensitivity(at 90% C.L.) to T1/20νββof 1.8×1028yr(5.6×1027yr) with 50 tons(5 tons) of fiducial136 Xe and 5 years exposure,while in the 50-ton case the corresponding sensitivity to the effective neutrino mass,mββ,could reach(5–12) meV,covering completely the allowed region of inverted neutrino mass ordering. 展开更多
关键词 double beta decay liquid scintillator JUNO
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Nuclear 0ν2βdecays in B-L symmetric SUSY model and in TeV scale left–right symmetric model
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作者 Jin-Lei Yang Chao-Hsi Chang Tai-Fu Feng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2022年第8期76-92,共17页
In this paper,we take the B-L supersymmetric standard model(B-LSSM)and TeV scale left–right symmetric model(LRSM)as two representations of the two kinds of new physics models to study the nuclear neutrinoless double ... In this paper,we take the B-L supersymmetric standard model(B-LSSM)and TeV scale left–right symmetric model(LRSM)as two representations of the two kinds of new physics models to study the nuclear neutrinoless double beta decays(0ν2β)so as to see the senses onto these two kinds of models when the decays are taken into account additionally.Within the parameter spaces allowed by all the existing experimental data,the decay half-life of the nucleus^(76)Ge and^(136)Xe,T_(12)^(0ν)(^(76)Ge,^(136)Xe),is precisely calculated and the results are presented properly.Based on the numerical results,we conclude that there is greater room for LRSM type models than for B-LSSM type models in foreseeable future experimental observations on the decays. 展开更多
关键词 B-LSSM QCD correction neutrinoless double beta decay LRSM
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Research on convergence of the nuclear matrix elements for 2νββ decays
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作者 Yue Hu Hantao Li Chengwei Dong 《Chinese Physics C》 SCIE CAS CSCD 2020年第12期171-176,共6页
In this work,the characteristics of 2νββ decays for six nuclei(36Ar,46Ca,48Ca,50Cr,70Zn,and 136Xe)in a mass range from A=36 to A=136 are studied within the nuclear shell model(NSM)framework.Calculations are present... In this work,the characteristics of 2νββ decays for six nuclei(36Ar,46Ca,48Ca,50Cr,70Zn,and 136Xe)in a mass range from A=36 to A=136 are studied within the nuclear shell model(NSM)framework.Calculations are presented for the half-lives,nuclear matrix elements(NMEs),phase space factors(G2ν),and convergence of the NMEs.The theoretical results agree well with the experimental data.In addition,we predict the half-lives of 2νββ decays for four nuclei.We focus on the convergence of the NMEs by analyzing the number of contributing intermediate 1+states(NC)for the nuclei of interest.We assume that NC is safely determined when the accumulated NMEs saturate 99.7%of the final calculated magnitude.From the calculations of the involved nuclei,we discover a connection between NC and the total number of intermediate 1+states(NT).According to the least squares fit,we conclude that the correlation is NC=(10.8±1.2)×N(0.29±0.02)T. 展开更多
关键词 two-neutrino double beta decay nuclear matrix elements CONVERGENCE
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2νββ-decay to first 2^+states with partial isospin symmetry restoration from spherical QRPA calculations
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作者 Dong-Liang Fang Amand Faessler 《Chinese Physics C》 SCIE CAS CSCD 2020年第8期139-146,共8页
Using partially restored isospin symmetry,we calculate the nuclear matrix elements for a special decay mode of a two-neutrino double beta decay–the decay to the first 2+excited states.Employing the realistic CD–Bonn... Using partially restored isospin symmetry,we calculate the nuclear matrix elements for a special decay mode of a two-neutrino double beta decay–the decay to the first 2+excited states.Employing the realistic CD–Bonn nuclear force,we analyze the dependence of the nuclear matrix elements on the isovector and isoscalar parts of proton–neutron particle–particle interactions.The dependence on the different nuclear matrix elements is observed,and the results are explained.We also provide the phase space factors using numerical electron wavefunctions and properly chosen excitation energies.Finally,we present our results for the half-lives of this decay mode for different nuclei. 展开更多
关键词 double beta decay quasi-particle random phase approximation nuclear matrix element
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Signal-background discrimination with convolutional neural networks in the PandaX-Ⅲ experiment using MC simulation 被引量:1
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作者 Hao Qiao ChunYu Lu +3 位作者 Xun Chen Ke Han XiangDong Ji SiGuang Wang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2018年第10期51-59,共9页
The PandaX-Ⅲ experiment will search for neutrinoless double beta decay of 136Xe with high pressure gaseous time projection chambers at the China Jin-Ping underground Laboratory. The tracking feature of gaseous detect... The PandaX-Ⅲ experiment will search for neutrinoless double beta decay of 136Xe with high pressure gaseous time projection chambers at the China Jin-Ping underground Laboratory. The tracking feature of gaseous detectors helps suppress the background level, resulting in the improvement of the detection sensitivity. We study a method based on the convolutional neural networks to discriminate double beta decay signals against the background from high energy gammas generated by 214Bi and 2^208 T1 decays based on detailed Monte Carlo simulation. Using the 2-dimensional projections of recorded tracks on two planes, the method successfully suppresses the background level by a factor larger than 100 with a high signal efficiency. An improvement of 62% on the efficiency ratio of Еs/√Еb is achieved in comparison with the baseline in the PandaX-Ⅲ conceptual design report. 展开更多
关键词 NEUTRINO double beta decay convolutional neural networks background suppression
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Phenomenological advantages of the normal neutrino mass ordering
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作者 Shao-Feng Ge Jing-yu Zhu 《Chinese Physics C》 SCIE CAS CSCD 2020年第8期33-39,共7页
The preference of the normal neutrino mass ordering from the recent cosmological constraint and the global fit of neutrino oscillation experiments does not seem like a wise choice at first glance since it obscures the... The preference of the normal neutrino mass ordering from the recent cosmological constraint and the global fit of neutrino oscillation experiments does not seem like a wise choice at first glance since it obscures the neutrinoless double beta decay and hence the Majorana nature of neutrinos.Contrary to this naive expectation,we point out that the actual situation is the opposite.The normal neutrino mass ordering opens the possibility of excluding the higher solar octant and simultaneously measuring the two Majorana CP phases in future 0ν2βexperiments.Especially,the funnel region will completely disappear if the solar mixing angle takes the higher octant.The combined precision measurement by the JUNO and Daya Bay experiments can significantly reduce the uncertainty in excluding the higher octant.With a typical O(meV)sensitivity on the effective mass|mee|,the neutrinoless double beta decay experiment can tell if the funnel region really exists and hence exclude the higher solar octant.With the sensitivity further improved to sub-meV,the two Majorana CP phases can be simultaneously determined.Thus,the normal neutrino mass ordering clearly shows phenomenological advantages over the inverted one. 展开更多
关键词 neutrino mass ordering higher solar octant neutrinoless double beta decay Majorana CP phases
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