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Science China(physics,Mechanics & Astronomy) 2025年第2期68卷 199-200页

作者： XueQing Yan State Key Laboratory of nuclear physics and Technology Peking UniversityBeijing 100871China

The intelligent control of accelerator particle beams,achieved through machine learning,offers a new opportunity for the design and regulation of high-power,high-intensity *** recent years,this technology has been applied in several practical *** instance,the DeepMind team successfully used reinforcement learning to control the plasma in a Tokamak device with 19 control magnets[1].

关键词： particle instance accelerator

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Modeling net-charge fluctuations in heavy-ion collisions at the LHC

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Chinese physics C 2025年第1期49卷 281-289页

作者： G.O.Ambaryan A.S.Chernyshov G.Kh.Eyyubova V.L.Korotkikh I.P.Lokhtin S.V.Petrushanko A.M.Snigirev E.E.Zabrodin physics Department Lomonosov Moscow State UniversityRU-119991 MoscowRussia Skobeltsyn Institute of nuclear physics Lomonosov Moscow State UniversityRU-119991 MoscowRussia Bogoliubov Laboratory of Theoretical physics Joint Institute for Nuclear ResearchRU-141980 DubnaRussia Department of physics University of OsloN-0316 OsloNorway

Analysis of Pb+Pb data for net-charge fluctuations at LHC energies using the HYDJET++model is *** strongly intensive quantities D and Σ were used to remove the effects related to system volume *** employed two versions of HYDJET++for the *** first one is the standard or default version,whereas the second one is a modification that takes into account explicit event-by-event conservation of the electric net-charge of produced *** inclusion of the canonical net-charge conservation in the model allows for better description of the experimental data obtained by the ALICE and CMS Collaborations.A comparison with calculations from other models is also presented.

关键词： relativistic heavy-ion collisions net-charge fluctuations strongly intensive variables canonical charge conservation

Establishing the vector-meson-exchange dominance for the short range interactions of light quarks

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Science China(physics,Mechanics & Astronomy) 2025年第3期68卷 190-191页

作者： Bing-Song Zou Department of physics Tsinghua UniversityBeijing100084China CAS Key Laboratory of Theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing100190China School of physics University of Chinese Academy of SciencesBeijing100049China Southern Center for nuclear-Science Theory(SCNT) Institute of Modern PhysicsChinese Academy of SciencesHuizhou516000China

Understanding the interactions between constituent quarks is one of the fundamental and challenging problems in hadron *** present,the constituent quark models have achieved great success in describing the properties of hadrons,whereas some long-standing disputes remain,especially for the short range interactions between constituent *** exploring the dynamic mechanism between u/d quarks,it is found that the one gluon exchange and/or vector meson exchange induced interactions may dominate the short range interactions[1].

关键词： quark exchange meson

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Machine learning for online control of particle accelerators

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Science China(physics,Mechanics & Astronomy) 2025年第2期68卷 94-104页

作者： Xiaolong Chen Zhijun Wang Yuan He Hong Zhao Chunguang Su Shuhui Liu Weilong Chen Xiaoying Zhao Xin Qi Kunxiang Sun Chao Jin Yimeng Chu Hongwei Zhao Institute of Modern physics Chinese Academy of SciencesLanzhou 730000China School of nuclear Science and Technology Lanzhou UniversityLanzhou 730000China School of nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Advanced Energy Science and Technonlogy Guangdong Laboratory Huizhou 516000China Department of physics Xiamen UniversityXiamen 361005China

Particle accelerators play a critical role in modern scientific ***,existing manual beam control methods heavily rely on experienced operators,leading to significant time consumption and potential challenges in managing next-generation accelerators characterized by higher beam current and stronger nonlinear *** this paper,we establish a dynamical foundation for designing the online adaptive controller of accelerators using machine *** provides a guarantee for dynamic controllability for a class of scientific instruments whose dynamics are described by spatial-temporal equations of motion but only part variables along the instruments under steady states are *** necessity of using historical time series of beam diagnostic data is *** strategies involve also employing a well-established virtual beamline of accelerators,by which various beam calibration scenarios that actual accelerators may encounter are *** the reinforcement learning algorithm is adopted to train the controller with the interaction to the virtual ***,the controller is seamlessly transitioned to real ion accelerators,enabling efficient online adaptive control and ***,the controller demonstrates significant robustness,effectively managing beams with diverse charge mass ratios without requiring *** a controller allows us to achieve the global control within the entire superconducting section of the China Accelerator Facility for Superheavy Elements.

关键词： nonlinear complex system adaptive control machine learning particle accelerator simulation to reality

A novel method for simultaneous measurement of^(222)Rn and^(220)Rn progeny concentrations measured by an alpha spectrometer

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nuclear Science and Techniques 2025年第1期36卷 127-139页

作者： Zhong-Kai Fan Jia-Le Sun Hao-Xuan Li Xiang-Ming Cai Hui Yang Shou-Kang Qiu Yan-Liang Tan Jian Shan School of nuclear Science and Technology University of South ChinaHengyang 421001China College of physics and Electronic Engineering Hengyang Normal UniversityHengyang 421008China

The accumulation of^(222)Rn and^(220)Rn progeny in poorly ventilated environments poses the risk of natural radiation exposure to the public.A previous study indicated that satisfactory results in determining the^(222)Rn and^(220)Rn progeny concentrations by measuring the total alpha counts at five time intervals within 560 min should be expected only in the case of high progeny concentrations in *** complete the measurement within a relatively short period and adapt it for simultaneous measurements at comparatively lower^(222)Rn and^(220)Rn progeny concentrations,a novel mathematical model was proposed based on the radioactive decay *** model employs a nonlinear fitting method to distinguish nuclides with overlapping spectra by utilizing the alpha particle counts of non-overlapping spectra within consecutive measurement cycles to obtain the concentrations of^(222)Rn and^(220)Rn progeny in *** verification experiments were conducted using an alpha *** experimental results demonstrate that the concentrations of^(222)Rn and^(220)Rn progeny calculated by the new method align more closely with the actual circumstances than those calculated by the total count method,and their relative uncertainties are all within±16%.Furthermore,the measurement time was reduced to 90 min,representing an acceleration of 84%.The improved capability of the new method in distinguishing alpha particles with similar energies emitted from ^(218)Po and^(212)Bi,both approximately 6 MeV,contributed to realizing more accurate *** proposed method has the potential advantage of measuring relatively low concentrations of^(222)Rn and^(220)Rn progeny in air more quickly via air filtration.

关键词： ^(222)Rn ^(220)Rn Progeny concentration Nonlinear fitting method Alpha spectrometer

Tetrahedral shape and Lambda impurity effect in 80Zr with a multidimensionally constrained relativistic Hartree-Bogoliubov model

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Chinese physics C 2025年第02期 141-150页

作者：杨丹荣宇婷 Department of physics Guangxi Normal University Guangxi Key Laboratory of nuclear physics and Technology Guangxi Normal University

This study investigated the tetrahedral structure in80Zr and Lambda（Λ） impurity effect inΛ81Zr using the multidimensionally constrained relativistic Hartree-Bogoliubov *** ground states of both80Zr andΛ81Zr exhibit a tetrahedral configuration,accompanied by prolate and axial-octupole shaped *** calculations reveal that there are changes in the deformation parameters β20,β30,and β32upon Λ binding to80Zr,except for β32whenΛ occupies *** to the two shape isomers,the Λ particle exhibits weaker binding energy in the tetrahedral state when occupying the 1/2+[000]（Λs） or 1/2-[110] single-particle *** contrast,the strongest binding occurs for the Λ particle in the 1/2-[101] state with tetrahedral ***,a large Λ separation energy may not necessarily correlate with a significant overlap between the density distributions of the Λ particle and nuclear core,particularly for tetrahedral hypernuclei.

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Vector meson’s spin alignments in high energy reactions

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Science China(physics,Mechanics & Astronomy) 2025年第1期68卷 1-16页

作者： Jin-Hui Chen Zuo-Tang Liang Yu-Gang Ma Xin-Li Sheng Qun Wang Key Laboratory of nuclear physics and Ion-beam Application(MoE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Institute of Frontier and Interdisciplinary Science Key Laboratory of Particle Physics and Particle Irradiation(MOE)Shandong UniversityQingdao 266237China INFN-Firenze Sesto Fiorentino FI 50019Italy Department of Modern physics University of Science and Technology of ChinaHefei 230026China School of Mechanics and physics Anhui University of Science and TechnologyHuainan 232001China

The global spin alignment of vector mesons has been observed by the STAR collaboration at the Relativistic Heavy Ion Collider(RHIC)at Brookhaven National Laboratory(BNL).It provides a unique opportunity to probe the correlation between the po-larized quark and antiquark in the strongly coupled quark-gluon plasma(sQGP)produced in relativistic heavy ion collisions,opening a new window to explore the properties of *** addition,spin alignments of vector mesons have also been observed in other high-energy particle collisions such as e^(+)e^(−)annihilations at high energies where hadron production is dominated by quark fragmentation *** results obtained are quite different from those obtained in heavy ion collisions where quark coalescence/combination mechanism dominates suggesting strong dependence on hadronization *** comprehensive studies in different hadronization processes are *** this article,we present a brief review of theoretical and experimen-tal advances in the study of vector meson’s spin alignments in a variety of high-energy particle collisions,with emphasis on hadronization mechanisms.

关键词： vector meson spin alignment global polarization relativistic heavy ion collisions fragmentation

Jet tagging with more-interaction particle transformer

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Chinese physics C 2025年第1期49卷 164-176页

作者： Yifan Wu Kun Wang Congqiao Li Huilin Qu Jingya Zhu College of Science University of Shanghai for Science and TechnologyShanghai 200093China School of physics and State Key Laboratory of nuclear physics and Technology Peking UniversityBeijing 100871China CERN EP DepartmentCH-1211 Geneva 23Switzerland School of physics and Electronics Henan UniversityKaifeng 475004China

In this paper,we introduce the More-Interaction Particle Transformer(MIParT),a novel deep-learning neural network designed for jet *** framework incorporates our own design,the More-Interaction Attention(MIA)mechanism,which increases the dimensionality of particle interaction *** tested MIParT using the top tagging and quark-gluon *** results show that MIParT not only matches the accuracy and AUC of LorentzNet and a series of Lorentz-equivariant methods,but also significantly outperforms the ParT model in background ***,it improves background rejection by approximately 25% with a signal efficiency of 30% on the top tagging dataset and by 3% on the quark-gluon ***,MIParT requires only 30% of the parameters and 53% of the computational complexity needed by ParT,proving that high performance can be achieved with reduced model *** very large datasets,we double the dimension of particle embeddings,referring to this variant as MIParT-Large(MIParT-L).We found that MIParT-L can further capitalize on the knowledge from large *** a model pre-trained on the 100M JetClass dataset,the background rejection performance of fine-tuned MIParT-L improves by 39% on the top tagging dataset and by 6% on the quark-gluon dataset,surpassing that of fine-tuned ***,the background rejection of fine-tuned MIParT-L improves by an additional 2% compared to that of fine-tuned *** results suggest that MIParT has the potential to increase the efficiency of benchmarks for jet tagging and event identification in particle physics.

关键词： jet tagging collider physics machine learning

The electromagnetic form factors and spin polarization of Λc+ in the process ■

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Chinese physics C 2025年第02期 23-30页

作者：陈诚闫冰谢聚军 Institute of Modern physics Chinese Academy of Sciences School of nuclear Sciences and Technology University of Chinese Academy of Sciences Southern Center for nuclear-Science Theory (SCNT) Institute of Modern PhysicsChinese Academy of Sciences

The total cross sections of the process ■ close to the threshold are calculated within the vector meson dominance *** is found that the theoretical results can describe the current experimental *** nontrivial near-threshold energy dependence of the total cross sections of the process ■ can be well reproduced by considering the contributions from charmonium-like states and the Coulomb *** particular,the results for the angular distribution parameters about the differential cross section are consistent with the experiments from the BESⅢ *** addition,the relative phase ΔΦ of the electromagnetic form factors is given,and the spin polarization of Λc+is predicted at center-mass energy 4.7 *** is hopeful that this work will provide a new perspective on the characteristics of the charmed baryon Λc+.

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A nuclide identification method ofγspectrum and model building based on the transformer

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nuclear Science and Techniques 2025年第1期36卷 80-93页

作者： Fei Li Chu-Yang Luo Ying-Zi Wen Sheng Lv Feng Cheng Guo-Qiang Zeng Jian-Feng Jiang Bing-Hai Li College of nuclear Technology and Automation Engineering Chengdu University of TechnologyChengdu 610000China Applied nuclear Technology in Geosciences Key Laboratory of Sichuan Province Chengdu 610000China Department of physics Universitat Politècnica de CatalunyaBarcelona 08028Spain Airborne Survey and Remote Sensing Center of nuclear Industry Shijiazhuang 050000China Hebei Key Laboratory of Airborne Detection and Remote Sensing Technology Shijiazhuang 050000China

In current neural network algorithms for nuclide identification in high-background,poor-resolution detectors,traditional network paradigms including back-propagation networks,convolutional neural networks,recurrent neural networks,etc.,have been limited in research on γ spectrum analysis because of their inherent mathematical *** is difficult to make progress in terms of training data requirements and prediction *** contrast to traditional network paradigms,network models based on the transformer structure have the characteristics of parallel computing,position encoding,and deep stacking,which have enabled good performance in natural language processing tasks in recent ***,in this paper,a transformer-based neural network (TBNN) model is proposed to achieve nuclide identification for the first ***,the Geant4 program was used to generate the basic single-nuclide energy spectrum through Monte Carlo simulations.A multi-nuclide energy spectrum database was established for neural network training using random matrices of γ-ray energy,activity,and *** on the encoder–decoder structure,a network topology based on the transformer was built,transforming the 1024-channel energy spectrum data into a 32×32 energy spectrum sequence as the model *** experiments and adjustments of model parameters,including the learning rate of the TBNN model,number of attention heads,and number of network stacking layers,the overall recognition rate reached 98.7%.Additionally,this database was used for training AI models such as back-propagation networks,convolutional neural networks,residual networks,and long shortterm memory neural networks,with overall recognition rates of 92.8%,95.3%,96.3%,and 96.6%,*** indicates that the TBNN model exhibited better nuclide identification among these AI models,providing an important reference and theoretical basis for the practical application of transformers in the qualitative and quantitativ

关键词： Nuclide identification Neural network Transformer