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Coupled-channel approach to Tcc+ including three-body effects

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arXiv 2021年

作者： Du, Meng-Lin Baru, Vadim Dong, Xiang-Kun Filin, Arseniy Guo, Feng-Kun Hanhart, Christoph Nefediev, Alexey Nieves, Juan Wang, Qian Institutos de Investigación de Paterna Apartado 22085 Valencia46071 Spain Institut für Theoretische Physik II Ruhr-Universität Bochum BochumD-44780 Germany Institute for Theoretical and Experimental Physics NRC Kurchatov Institute Moscow117218 Russia CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China School of Physical Sciences University of Chinese Academy of Sciences Beijing100049 China Institute for Advanced Simulation Institut für Kernphysik Jülich Center for Hadron Physics Forschungszentrum Jülich JülichD-52425 Germany P.N. Lebedev Physical Institute The Russian Academy of Sciences Leninskiy Prospect 53 Moscow119991 Russia Moscow Institute of Physics and Technology Institutsky lane 9 Moscow Region Dolgoprudny141700 Russia Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum Matter South China Normal University Guangzhou510006 China Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Southern Nuclear Science Computing Center South China Normal University Guangzhou510006 China

A coupled-channel approach is applied to the charged tetraquark state Tcc+ recently discovered by the LHCb Collaboration. The parameters of the interaction are fixed by a fit to the observed line shape in the three-body D0D0π+ channel. Special attention is paid to the three-body dynamics in the Tcc+ due to the finite life time of the D∗. An approach to the Tcc+ is argued to be self-consistent only if both manifestations of the three-body dynamics, the pion exchange between the D and D∗ mesons and the finite D∗ width, are taken into account simultaneously to ensure that three-body unitarity is preserved. This is especially important to precisely extract the pole position in the complex energy plane whose imaginary part is very sensitive to the details of the coupled-channel scheme employed. The D0D0 and D0D+ invariant mass distributions, predicted based on this analysis, are in good agreement with the LHCb data. The low-energy expansion of the D∗D scattering amplitude is performed and the low-energy constants (the scattering length and effective range) are extracted. The compositeness parameter of the Tcc+ is found to be close to unity, which implies that the Tcc+ is a hadronic molecule generated by the interactions in the D∗+D0 and D∗0D+ channels. Employing heavy-quark spin symmetry, an isoscalar D∗D∗ molecular partner of the Tcc+ with JP = 1+ is predicted under the assumption that the DD∗-D∗D∗ coupled-channel effects can be neglected. Copyright © 2021, The Authors. All rights reserved.

关键词： Hadrons

Control of electron beam polarization in the bubble regime of laser-wakefield acceleration

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arXiv 2022年

作者： Fan, H.C. Liu, X.Y. Li, XiaoFeng Qu, J.F. Yu, Q. Kong, Q. Weng, S.M. Chen, M. Büscher, M. Gibbon, P. Kawata, S. Sheng, Z.M. Institute of Modern Physics Department of Nuclear Science and Technology Fudan University Shanghai200433 China Institute for Advanced Simulation Jülich Supercomputing Centre Forschungszentrum Jülich Jülich52425 Germany School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China Collaborative Innovation Center of IFSA Shanghai Jiao Tong University Shanghai200240 China State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai201800 China Forschungszentrum Jülich Wilhelm-Johnen-Str. 1 Jülich52425 Germany Institut für Laser- und Plasmaphysik Heinrich-Heine-Universität Düsseldorf Universitätsstr. 1 Düsseldorf40225 Germany Centre for Mathematical Plasma Astrophysics Katholieke Universiteit Leuven Leuven3000 Belgium Graduate School of Engineering Utsunomiya University Utsunomiya321-8585 Japan SUPA Department of Physics University of Strathclyde GlasgowG4 0NG United Kingdom Tsung-Dao Lee Institute Shanghai Jiao Tong University Shanghai200240 China

Electron beam polarization in the bubble regime of the interaction between a high-intensity laser and a longitudinally pre-polarized plasma is investigated by means of the Thomas-Bargmann-Michel-Telegdi equation. Using a test-particle model, the dependence of the accelerated electron polarization on the bubble geometry is analyzed in detail. Tracking the polarization dynamics of individual electrons reveals that although the spin direction changes during both the self-injection process and acceleration phase, the former has the biggest impact. For nearly spherical bubbles, the polarization of electron beam persists after capture and acceleration in the bubble. By contrast, for aspherical bubble shapes, the electron beam becomes rapidly depolarized, and the net polarization direction can even reverse in the case of a oblate spheroidal bubble. These findings are confirmed via particle-in-cell simulations. © 2022, CC BY.

关键词： Electrons

Chemical short-range ordering and its strengthening effect in refractory high-entropy alloys

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Physical Review B 2021年第10期103卷 104107-104107页

作者： S. D. Wang X. J. Liu Z. F. Lei D. Y. Lin F. G. Bian C. M. Yang M. Y. Jiao Q. Du H. Wang Y. Wu S. H. Jiang Z. P. Lu Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 People's Republic of China Software Center for High Performance Numerical Simulation Chinese Academy of Engineering Physics Beijing 100088 People's Republic of China Institute of Applied Physics and Computational Mathematics Beijing 100088 People's Republic of China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201204 People's Republic of China

In this work, we perform first-principles calculations, coupled with synchrotron small-angle x-ray scattering (SAXS) to investigate electronic origins of the chemical short-range ordering (CSRO) and to reveal the relationship between CSROs and mechanical properties in a typical bcc (body-centered-cubic) TiZrHfNb high-entropy alloys (HEAs). It was found that existence of an appropriate degree of CSROs not only stabilizes the HEA lattice structure, but also enhances the hardness, elastic modulus, and ideal strength. Comprehensive electronic structure analyses uncover that the reduction of d electrons at the Fermi level due to the development of (Ti, Zr)-based CSROs stabilizes the bcc HEA, and the CSRO-induced strengthening is attributed to the local lattice distortion and the d-electron transfer from high-energy to low-energy states under applied strains. This finding not only gives insight into understanding the nature of CSRO strengthening in bcc HEAs, but also provides a paradigm for achieving desired mechanical properties via tailoring CSROs in HEAs.

关键词： Density of states Elasticity Electronic structure First-principles calculations Structural properties Transition metal alloys Density functional theory Small-angle x-ray scattering

Effective range expansion for narrow near-threshold resonances

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arXiv 2021年

作者： Baru, Vadim Dong, Xiang-Kun Du, Meng-Lin Filin, Arseniy Guo, Feng-Kun Hanhart, Christoph Nefediev, Alexey Nieves, Juan Wang, Qian Institut für Theoretische Physik II Ruhr-Universität Bochum BochumD-44780 Germany CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Zhong Guan Cun East Street 55 Beijing100190 China School of Physical Sciences University of Chinese Academy of Sciences Beijing100049 China Institutos de Investigación de Paterna C/Catedrático José Beltrán 2 Paterna ValenciaE-46980 Spain Institute for Advanced Simulation Institut für Kernphysik Jülich Center for Hadron Physics Forschungszentrum Jülich JülichD-52425 Germany P.N. Lebedev Physical Institute the Russian Academy of Sciences Leninskiy Prospect 53 Moscow119991 Russia Moscow Institute of Physics and Technology 141700 Institutsky lane 9 Dolgoprudny Moscow Region Russia Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum Matter South China Normal University Guangzhou510006 China Institute of High Energy Physics Chinese Academy of Sciences Beijing100049 China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Southern Nuclear Science Computing Center South China Normal University Guangzhou510006 China

We discuss some general features of the effective range expansion, the content of its parameters with respect to the nature of the pertinent near-threshold states and the necessary modifications in the presence of coupled channels, isospin violations and unstable constituents. As illustrative examples, we analyse the properties of the χc1(3872) and Tcc+ states supporting the claim that these exotic states have a predominantly molecular nature. Copyright © 2021, The Authors. All rights reserved.

关键词： Expansion

QCD θ-vacuum energy and axion properties

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arXiv 2020年

作者： Lu, Zhen-Yan Du, Meng-Lin Guo, Feng-Kun Meißner, Ulf-G Vonk, Thomas School of Physics and Electronic Science Hunan University of Science and Technology Xiangtan411201 China CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China Helmholtz-Institut für Strahlen- und Kernphysik Bethe Center for Theoretical Physics Universität Bonn BonnD-53115 Germany School of Physical Sciences University of Chinese Academy of Sciences Beijing100049 China Institute for Advanced Simulation Institut für Kernphysik Jülich Center for Hadron Physics Forschungszentrum Jülich JülichD-52425 Germany Tbilisi State University Tbilisi0186 Georgia

At low energies, the strong interaction is governed by the Goldstone bosons associated with the spontaneous chiral symmetry breaking, which can be systematically described by chiral perturbation theory. In this paper, we apply this theory to study the θvacuum energy density and hence the QCD axion potential up to next-to-leading order with N non-degenerate quark masses. By setting N = 3, we then derive the axion mass, self-coupling, topological susceptibility and the normalized fourth cumulant both analytically and numerically, taking the strong isospin breaking effects into account. In addition, the model-independent part of the axion-photon coupling, which is important for axion search experiments, is also extracted from the chiral Lagrangian supplemented with the anomalous terms up to O(p6). Copyright © 2020, The Authors. All rights reserved.

关键词： Perturbation techniques

SVM-based deep stacking networks

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arXiv 2019年

作者： Wang, Jingyuan Feng, Kai Wu, Junjie MOE Engineering Research Center of Advanced Computer Application Technology School of Computer Science Engineering Beihang University Beijing100191 China Beijing Key Laboratory of Emergency Support Simulation Technologies for City Operations School of Economics and Management Beihang University Beijing100191 China Beijing Advanced Innovation Center for Big Data and Brain Computing Beihang University Beijing100191 China

The deep network model, with the majority built on neural networks, has been proved to be a powerful framework to represent complex data for high performance machine learning. In recent years, more and more studies turn to nonneural network approaches to build diverse deep structures, and the Deep Stacking Network (DSN) model is one of such approaches that uses stacked easy-to-learn blocks to build a parameter-training-parallelizable deep network. In this paper, we propose a novel SVM-based Deep Stacking Network (SVM-DSN), which uses the DSN architecture to organize linear SVM classifiers for deep learning. A BP-like layer tuning scheme is also proposed to ensure holistic and local optimizations of stacked SVMs simultaneously. Some good math properties of SVM, such as the convex optimization, is introduced into the DSN framework by our model. From a global view, SVM-DSN can iteratively extract data representations layer by layer as a deep neural network but with parallelizability, and from a local view, each stacked SVM can converge to its optimal solution and obtain the support vectors, which compared with neural networks could lead to interesting improvements in anti-saturation and interpretability. Experimental results on both image and text data sets demonstrate the excellent performances of SVM-DSN compared with some competitive benchmark models. Copyright © 2019, The Authors. All rights reserved.

关键词： Convex optimization

Improving hazard analysis of integrated modular avionics system based on system-theoretic process analysis 18th

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Improving hazard analysis of integrated modular avionics sys...

18th AIAA aviation technology, Integration, and Operations Conference, 2018

作者： Rong, Hao Gu, Qingfan Chen, Zhixiong Xu, Desheng China National Aeronautical Radio Electronics Research Institute Civil Aviation Department No.432 Zi Yue Road Shanghai China Science and Technology on Avionics Integration Laboratory Civil Aviation Department No.432 Zi Yue Road Shanghai China State Key Laboratory for Civil Aircraft Flight Simulation Commercial Aircraft Corporation of China Ltd. No.5188 Jin Ke Road Shanghai China

ISBN: (纸本)9781624105562

Integrated modular avionics systems bring new concepts and benefits for function integration and resource utilization in developing advanced aircraft avionics, as well as a series of challenges related to hazard analysis in components interaction and functions operation. When software applications provided independently by the subsystem developers are integrated onto the IMA hardware platform, it is very difficult for designers to understand and predict how the system will behave and what interaction hazards could occur. Although the ARP 4761-based safety analysis methods have solved a large number of safety problems on the development of civil aircraft and system designs in early times, there are some limitations when analyzing more and more complex integrated modular avionics systems in modern times. To gain a good or better understanding and a comprehensive awareness of applications interaction hazards in today’s more complex, software-intensive IMA systems, it is significant to use a method to consider these new causal factors that are not handled by the older techniques and to provide more guidance to the analyst in performing hazard analysis. System-Theoretic Process Analysis (STPA) is one of typical systemic hazard analysis methods. STPA has its foundation in a new accident causality model called STAMP (System-Theoretic Accident Model and Process). STAMP was proposed based on the cybernetics of systems theory. In STAMP, the dysfunctional interactions and requirements flaws during operation are primary types of inadequate control. The STPA-based hazard analysis method is extended in this paper to account for behavior that emerges when software applications are integrated and make functional interaction. This method will be capable of modeling the new causal factors that contribute to component interaction hazards. The paper illustrates the new method with a case that includes real-world avionics display functions, this application of the proposed method will b

关键词： Hazards

Influence mechanism of Cu on high temperature oxidation behavior of titanium alloys

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Influence mechanism of Cu on high temperature oxidation beha...

Chinese Materials Conference, 2018

作者： Chen, Hang Mi, Guang-Bao Li, Pei-Jie Cao, Chun-Xiao National Center of Novel Materials for International Research Tsinghua University Beijing100084 China Aviation Key Laboratory of Science and Technology on Advanced Titanium Alloys Beijing Institute of Aeronautical Materials Beijing100095 China Beijing Engineering Research Center of Graphene and Application Beijing100095 China

ISBN: (纸本)9783035713848

The oxidation behavior and mechanism of Ti-Cu alloys (0≤w(Cu)≤20%) in the temperature range of 1000°C~1300°C were studied by thermogravimetric analysis(TGA) combined with SEM, EDS and XRD analysis methods. The results showed that the oxidation rates of Ti-Cu alloys increased sharply when the temperature rised above 1000 °C. The oxidation products had a three-layer structure, from the outside to the inside, which were dense outer oxide layer of TiO2, porous inner oxide layer of low valence oxide of Ti and Cu-enriched layer. With the increase of the temperature, the thicknesses of oxide layers of Ti-Cu alloy increased and the Cu-enriched phase increased gradually and melts. The melting Cu-enriched phase flowed to the oxidation surface along the grain boundaries of the oxide layer. The high temperature oxidation resistance of Ti-Cu alloys declined with the increase of Cu content. The main reason is that more liquid Cu-enriched phase is formed and flows to the oxidation surface along the oxide grain boundaries in the Ti-Cu alloy, and Ti and O ions can diffuse more easily along the liquid Cu-enriched phase, which increases the oxidation rates. © 2019 Trans Tech Publications, Switzerland.

关键词： Binary alloys

Bionic Optimization Design of Electronic Nose Chamber for Oil and Gas Detection

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Journal of Bionic Engineering 2018年第3期15卷 533-544页

作者： Zhiyong Chang Youhong Sun Yuchen Zhang Yanli Gao Xiaohui Weng Donghui Chen Liewe David Jun Xie Key Lab of Advanced Technologies of Materials Ministry of Education School of Materials Science and Engineering Southwest Jiaotong University Chengdu 610031 China Key Laboratory of Bionic Engineering Ministry of Education Jilin University Changchun 130022 China National-Local Joint Engineering Laboratory of In-situ Conversion Drilling and Exploitation Technology for Oil Shale Jilin University Changchun 130021 China College of Construction Engineering Jilin University Changchun 130022 China Clinical Medicine Bethune First Hospital of Jilin University Changchun 130021China College of Mechanical Science and Engineering Jilin University Changchun 130022 China School of Computing and Technology the University of Gloucestershire The Park Cheltenham GL50 2RH UK Air Combat Service Academy Air Force Aviation University Changchun 130021 China

In this paper, a miniaturized bionic electronic nose system is developed in order to solve the problems arising in oil and gas detection for large size and inflexible operation in downhole. The bionic electronic nose chamber is designed by mimicking human nasal turbinate structure, V-groove structure on shark skin surface and flow field distribution around skin surface. The sensitivity of the bionic electronic nose system is investigated through experimentation. Radial Basis Function （RBF） and Support Vector Machines （SVM） of 10-fold cross validation are used to compare the recognition performance of the bionic electronic nose system and common one. The results show that the sensitivity of the bionic electronic nose system with bionic composite chamber （chamber B） is significantly improved compared with that with common chamber （chamber A）. The recognition rate of chamber B is 4.27% higher than that of chamber A for the RBF algorithm, while for the SVM algorithm, the recognition rate of chamber B is 5.69% higher than that of chamber A. The three-dimensional simulation model of the chamber is built and verified by Computational Fluid Dynamics （CFD） simulation analysis. The number of vortices in chamber B is fewer than that in chamber A. The airflow velocity near the sensors inside chamber B is slower than that inside chamber A. The vortex intensity near the sensors in chamber B is 2.27 times as much as that in chamber A, which facilitates gas molecules to fully contact with the sensor surface and increases the intensity of sensor signal, and the contact strength and time between odorant molecules and sensor surface. Based on the theoretical investigation and test validation, it is believed that the proposed bionic electronic nose system with bionic composite chamber has potential for oil and gas detection in downhole.

关键词： electronic nose bionic chamber sensors oil gas detection