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Flavor mixing and solution structures in Dyson–Schwinger equations for a two-flavor system

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Communications in Theoretical physics 2024年第10期76卷 64-77页

作者： Xue-ao Chao Yu-xin Liu Department of physics and State Key Laboratory of nuclear physics and Technology Peking University Collaborative Innovation Center of Quantum Matter Center for high energy physics Peking University

We solved the Dyson–Schwinger(DS) equations for a two-flavor system with symmetry to study its flavor mixing effects. Initially, we employed the point interaction model and bare vertex approximation to reveal the structure of the solutions. Using the point interaction model, the DS equations can be solved analytically, and we found that these solutions can be classified into three groups, each forming an ellipse. These solutions exhibit SO(2) symmetry, while the original SU(2)symmetry at the Lagrangian level is dynamically broken to SO(2), corresponding to the emergence of flavor mixing effects. However, this flavor mixing effect does not manifest in the final physical *** utilizing the system's SO(2) symmetry, we can diagonalize the propagators of the DS equations,eliminating the flavor mixing effect but causing the originally degenerate masses at the Lagrangian level to split. These mass eigenstates have identical quantum numbers but different masses. If we can correspond these to quark particles of different generations, we can explain why the three generations of quarks have different masses and obtain the corresponding quark mass spectrum. Finally, we provide the corresponding numerical results using a more realistic interaction model.

关键词： dynamic symmetry breaking Dyson-Schwinger equation flavor change mass splitting

Spin asymmetry and dipole moments inτ-pair production with ultraperipheral heavy ion collisions

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Science China(physics,Mechanics & Astronomy) 2024年第8期67卷 15-21页

作者： Dingyu Shao Bin Yan Shu-Run Yuan Cheng Zhang Department of physics Center for Field Theory and Particle PhysicsFudan UniversityShanghai 200433China Key Laboratory of nuclear physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200433China Shanghai research Center for Theoretical nuclear physics National Natural Science Foundation of China(NSFC)and Fudan UniversityShanghai 200438China Institute of high energy physics Chinese Academy of SciencesBeijing 100049China School of physics Peking UniversityBeijing 100871China

The anomalous magnetic(MDM)and electric(EDM)dipole moments of theτlepton serve as crucial indicators of new physics beyond the standard *** azimuthal angular asymmetry as a novel tool in ultraperipheral collisions(UPCs),we attain unparalleled precision in the study of these key *** by the highly linear polarization of coherent photons,this method uniquely enables both the MDM and EDM to contribute to the cos 2φangular distribution in similar ***,our approach substantially narrows the parameter space,excluding more than half of it compared to expected UPC-based measurements reliant solely on the total *** method not only provides improved constraints but also minimizes the need for additional theoretical assumptions,and offers a novel avenue to probe the EDM effects.

关键词： ultraperipheral collisions magnetic and electric dipole moments spin asymmetry

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The energy response of LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals for GECAM

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nuclear Science and Techniques 2024年第2期35卷 110-122页

作者： Pei-Yi Feng Xi-Lei Sun Zheng-Hua An Yong Deng Cheng-Er Wang Huang Jiang Jun-Jie Li Da-Li Zhang Xin-Qiao Li Shao-Lin Xiong Chao Zheng Ke Gong Sheng Yang Xiao-Jing Liu Min Gao Xiang-Yang Wen Ya-Qing liu Yan-Bing Xu Xiao-Yun Zhao Jia-Cong Liu Fan Zhang Hong Lu Particle and Astrophysics Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Experimental physics Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China State Key Laboratory of Particle Detection and Electronics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of nuclear Science and Technology University of South ChinaHengyang 421001China National Engineering research Center for Rare Earth Grirem Advanced Materials Co.Ltd.and General Research Institute for Nonferrous MetalsBeijing 100088China

The GECAM series of satellites utilizes LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals as sensitive materials for gamma-ray detectors(GRDs).To investigate the nonlinearity in the detection of low-energy gamma rays and address the errors in the calibration of the E-C relationship,comprehensive tests and comparative studies of the three aforementioned crystals were conducted using Compton electrons,radioactive sources,and mono-energetic *** nonlinearity test results of the Compton electrons and X-rays demonstrated substantial differences,with all three crystals presenting a higher nonlinearity for X/-rays than for Compton *** the LaBr_(3)(Ce)and LaBr_(3)(Ce,Sr)crystals having higher absolute light yields,they exhibited a noticeable nonlinear decrease in the light yield,especially at energies below 400 *** NaI(Tl)crystal demonstrated an"excess"light output in the 6-200 keV range,reaching a maximum"excess"of 9.2%at 30 keV in the X-ray testing and up to 15.5%at 14 keV during Compton electron testing,indicating a significant advantage in the detection of low-energy gamma ***,we explored the underlying causes of the observed nonlinearity in these *** study not only elucidates the detector responses of GECAM,but also initiates a comprehensive investigation of the nonlinearity of domestically produced lanthanum bromide and sodium iodide crystals.

关键词： LaBr_(3)(Ce)detector LaBr_(3)(Ce,Sr)detector NaI(Tl)detector GECAM energy response Light yield nonlinearity

Measurement of the neutron-induced total cross sections of ^(nat)Pb from 0.3 eV to 20 MeV on the Back-n at CSNS

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nuclear Science and Techniques 2024年第2期35卷 85-93页

作者： Jie-Ming Xue Song Feng Yong-Hao Chen Han Yi Min Xiao Pin-Jing Cheng Xin-Xiang Li Rong Liu Yi-Wei Yang Zi-Jie Han Da-Jun Zhao Hao-Qiang Wang Bao-Qian Li Ji-Rong Zhao Lei-Xun Tang Wen Luo Bo Zheng School of nuclear Science and Technology University of South ChinaHengyang 421001China Institute of high energy physics Chinese Academy of Sciences(CAS)Beijing 100049China Spallation Neutron Source Science Center Dongguan 523803China Institute of nuclear physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China

The neutron-induced total cross sections of natural lead have been measured in a wide energy range(0.3 eV-20 MeV)on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron *** energy was determined by the neutron total cross-section spectrometer using the time-of-flight technique.A fast multi-cell fission chamber was used as the neutron detector,and a 10-mm-thick high-purity natural lead sample was employed for the neutron transmission *** on-beam background was determined using Co,In,Ag,and Cd *** excitation function of ^(nat)Pb(n,tot)reaction below 20 MeV was calculated using the TALYS-1.96 nuclear-reaction modeling *** present results were compared with previous results,the evaluated data available in the five major evaluated nuclear data libraries(i.e.,ENDF/B-VIII.0,JEFF-3.3,JENDL-5,CENDL-3.2,and BROND-3.1),and the theoretical calculation *** agreement was found between the new results and those of previous experiments and with the theoretical curves in the corresponding *** measurement obtained the neutron total cross section of natural lead with good accuracy over a wide energy range and added experimental data in the resonance energy *** provides more reliable experimental data for nuclear engineering design and nuclear data evaluation of lead.

关键词： Neutron-induced total cross section Natural lead Time-of-flight TALYS-1.96 CSNS Back-n white neutron beamline

New measurement of the neutron-induced total cross-sections of^(nat)Cr in a wide energy range on the Back-n at CSNS

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Chinese physics C 2024年第10期48卷 168-175页

作者： Baoqian Li Min Xiao Yonghao Chen Jieming Xue Xinxiang Li Han Yi Pinjing Cheng Rong Liu Yiwei Yang Zijie Han Dajun Zhao Haoqiang Wang Jirong Zhao Peng Luan Jing Liu Zijun Liu Chaomin Chen Wen Luo Bo Zheng Song Feng School of nuclear Science and Technology University of South ChinaHengyang 421001China Institute of high energy physics Chinese Academy of SciencesBeijing 100049China Spallation Neutron Source Science Center Dongguan 523803China Institute of nuclear physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China

The neutron total cross-section of ^(nat)Cr plays a crucial role in new nuclear engineering design and fundamental science.A new measurement of the neutron-induced total cross-sections of ^(nat)Cr was performed using the transmission method on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source(CSNS).The neutron energy was determined using the time-of-flight *** neutron total cross-sections of ^(nat)Cr were obtained across a broad energy range(0.3 eV−20 MeV)in one experiment for the first *** resulting effective total cross-sections were compared with the existing experimental data in different energy ranges,which revealed good agreement with the evaluated *** calculation of the total cross-section in the energy range of 1.5 to 20 MeV was then conducted using TALYS-1.96 and compared with the present *** measurement provides a high-quality total cross-section of ^(nat)Cr,including detailed uncertainty data across a wide energy range,offering a valuable reference for nuclear data re-evaluation and nuclear engineering design.

关键词： neutron total cross-section natural chromium Back-n white neutron beamline NTOX

Comprehensive analysis of uncertainty quantification for the^(58)Ni(n,p)^(58)Co reaction cross section

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Chinese physics C 2024年第9期48卷 170-175页

作者： Mahesh Choudhary Aman Sharma Namrata Singh Mahima Upadhyay Punit Dubey A.Gandhi Akash Hingu G Mishra Sukanya De L.S.Danu Ajay Kumar R.G.Thomas Saurav Sood Sajin Prasad S.Mukherjee I.N.Ruskov Yu.N.Kopatch A.Kumar Department of physics Banaras Hindu UniversityVaranasi 221005India Horia Hulubei National Institute of physics and nuclear Engineering-IFIN-HH Bucharest 077125Romania Department of physics The Maharaja Sayajirao University of BarodaVadodara 390002India nuclear physics Division Bhabha Atomic Research CentreMumbai 400085India Health physics Division Bhabha Atomic Research CentreMumbai 400085India Department of Electrical Power Engineering Brno University of TechnologyBrno 61600Czech Republic Institute for nuclear research and nuclear energy Bulgarian Academy of SciencesSofia 1784Bulgaria Joint Institute for nuclear research(JINR) Dubna 141980Russia

In this study,we measured the^(58)Ni(n,p)^(58)Co reaction cross section with neutron energies of 1.06,1.86,and 2.85 *** cross section was measured using neutron activation techniques andγ-ray spectroscopy,and it was compared with cross section data available in the ***,we calculated the covariance matrix of the measured cross section for the aforementioned nuclear *** uncertainties of the theoretical calculation for^(58)Ni(n,p)^(58)Co reaction cross section were calculated via Monte Carlo *** this study,we used uncertainties in the optical model and level density parameters to calculate uncertainties in the theoretical cross *** theoretical calculations were performed by using *** this study,we aim to analyze the effect of uncertainties of the nuclear model input as well as different experimental variables used to obtain the values of reaction cross section.

关键词： ^(58)Ni(n p)^(58)Co reaction γ-ray spectroscopy uncertainty quantification of cross section covariance analysis

Measurement of yields and angular distributions ofγ-quanta from the interaction of 14.1 MeV neutrons with oxygen,phosphorus,and sulfur

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Chinese physics C 2024年第3期48卷 79-92页

作者： D.N.Grozdanov N.A.Fedorov S.B.Dabylova Yu.N.Kopatch I.N.Ruskov V.R.Skoy T.Yu.Tretyakova C.Hramco P.I.Kharlamov G.V.Pampushik P.G.Filonchik A.V.Andreev Joint Institute for nuclear research(JINR) DubnaRussia Institute for nuclear research and nuclear energy Bulgarian Academy of SciencesSofiaBulgaria Faculty of physics Lomonosov Moscow State UniversityMoscowRussia L.N.Gumilyov Eurasian National University AstanaKazakhstan Skobeltsyn Institute of nuclear physics Moscow State UniversityMoscowRussia Institute of Chemistry of Moldova ChisinauRepublic of Moldova Moscow Institute of physics and Technology MoscowRussia

A study of the inelastic scattering of neutrons with an energy of 14.1 MeV on the nuclei of oxygen,phosphorus,and sulfur was performed at the TANGRA facility at JINR(Dubna).The experiment aimed to refine existing data and obtain new data on the yields and angular distributions ofγ-quanta emitted by the studied nuclei due to neutron-induced nuclear reactions using the tagged neutron *** types of detector systems were used to registerγ-***γ-ray yields were measured using a high-purity germanium(HPGe)*** angular distributions ofγ-rays were obtained using a system of 18 scintillation detectors based on bismuth germanite Bi_(4)Ge_(3)O_(12)(BGO)located around the *** performed experiments measured the yields of two transitions for the reaction of tagged neutrons with 16O,nine transitions for the reaction with ^(31)P,and nine transitions for the reaction with ^(32)S for the first *** angular anisotropy of theγ-radiation accompanying the inelastic scattering of neutrons with an energy of 14.1 MeV on ^(31)P nuclei was also measured for the first time.

关键词： tagged neutron method yields of gamma-quanta high-resolution gamma-spectrometry neutron-nuclear reactions neutron scattering

Invisible and semi-invisible decays of bottom baryons

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Chinese physics C 2024年第8期48卷 127-139页

作者： Yong Zheng Jian-Nan Ding Dong-Hao Li Lei-Yi Li Cai-Dian Lü Fu-Sheng Yu MOE Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China School of nuclear Science and Technology Lanzhou UniversityLanzhou 730000China Center for high energy physics Peking UniversityBeijing 100871China Institute of high energy physics CASBeijing 100049China School of Physical Sciences University of Chinese Academy of SciencesBeijing 101408China

The similar densities of dark matter and baryons in the universe imply that they may arise from the same ultraviolet model.B-Mesogenesis,which assumes dark matter is charged under the baryon number,attempts to simultaneously explain the origin of baryon asymmetry and dark matter in the *** particular,B-Mesogenesis may induce bottom-baryon decays into invisible or semi-invisible final states,which provide a distinctive signal for probing this *** this work,we systematically study the invisible decays of bottom baryons into dark matter and the semi-invisible decays of bottom baryons into a meson or a photon together with a dark matter *** particular,the fully invisible decay can reveal the stable particles in *** QCD-based frameworks are used to calculate the hadronic matrix elements under the B-Mesogenesis *** estimate the constraints on the Wilson coefficients or the product of some new physics couplings with the Wilson coefficients according to the semi-invisible and invisible decays of bottom baryons detectable at future colliders.

关键词： baryon asymmetry dark matter B-Mesogenesis invisible and semi-invisible decay bottom baryons

Nondestructive technique for identifying nuclides using neutron resonance transmission analysis at CSNS Back-n

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nuclear Science and Techniques 2024年第1期35卷 178-187页

作者： Sheng-Da Tang Yong-Hao Chen Jing-Yu Tang Rui-Rui Fan Qiang Li Gong Li Dong Liu Zheng-Yao Jin Xing-Zhu Cui Tian-Xiang Chen Yi-Wei Yang Rong Liu Han Yi Yang Li Zhen Yang Qi An Hao-Fan Bai Jiang-Bo Bai Jie Bao Ping Cao Qi-Ping Chen Zhen Chen Zeng-Qi Cui An-Chuan Fan Chang-Qing Feng Fan-Zhen Feng Ke-Qing Gao Min-Hao Gu Chang-Cai Han Zi-Jie Han Guo-Zhu He Yong-Cheng He Yang Hong Yi-Wei Hu Han-Xiong Huang Wei-Hua Jia Hao-yu Jiang Wei Jiang Zhi-jie Jiang Ling Kang Bo Li Chao Li Jia-Wen Li Xiao Li Jie Liu Shu-Bin Liu Guang-Yuan Luan Chang-Jun Ning Bin-Bin Qi Jie Ren Zhi-Zhou Ren Xi-Chao Ruan Zhao-Hui Song Kang Sun Zhi-Xin Tan Li-Jiao Wang Peng-Cheng Wang Zhao-Hui Wang Zhong-Wei Wen Xiao-Guang Wu Xuan Wu Li-Kun Xie Yong-Ji Yu Guo-Hui Zhang Lin-Hao Zhang Mo-Han Zhang Qi-Wei Zhang Xian-Peng Zhang Yu-Liang Zhang Yue Zhang Zhi-Yong Zhang Mao-Yuan Zhao Lu-Ping Zhou Zhi-Hao Zhou Ke-Jun Zhu Sino-French Institute of nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China Institute of high-energy physics Chinese Academy of Sciences(CAS)Beijing 100049China Spallation Neutron Source Science Center Dongguan 523803China School of nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Particle Detection and Electronics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China USTC Archaeometry Laboratory University of Science and Technology of ChinaHefei 230026China Institute of nuclear physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China Department of Modern physics University of Science and Technology of ChinaHefei 230026China State Key Laboratory of nuclear physics and Technology School of PhysicsPeking UniversityBeijing 100871China Key Laboratory of nuclear Data China Institute of Atomic EnergyBeijing 102413China Northwest Institute of nuclear Technology Xi’an 710024China University of Chinese Academy of Sciences Beijing 100049China

Nondestructive and noninvasive neutron assays are essential applications of neutron *** resonance transmission analysis(NRTA)is a powerful nondestructive method for investigating the elemental composition of an *** back-streaming neutron line(Back-n)is a newly built time-of-flight facility at the China Spallation Neutron Source(CSNS)that provides neutrons in the eV to 300 MeV range.A feasibility study of the NRTA method for nuclide identification was conducted at the CSNS Back-n via two test *** results demonstrate that it is feasible to identify different elements and isotopes in samples using the NRTA method at *** study reveals its potential future applications.

关键词： CSNS White neutron beam NRTA Nuclide identification Nondestructive method