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arXiv 2021年

作者： Hong, Qi Wang, Qi College of Science Nanjing University of Aeronautics and Astronautics Nanjing210016 China MIIT Nanjing211106 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex System Department of Mathematics University of South Carolina ColumbiaSC29208 United States

We present a novel computational modeling framework to numerically investigate fluid-structure interaction in viscous fluids using the phase field embedding method. Each rigid body or elastic structure immersed in the incompressible viscous fluid matrix, grossly referred to as the particle in this paper, is identified by a volume preserving phase field. The motion of the particle is driven by the fluid velocity in the matrix for passive particles or combined with its self-propelling velocity for active particles. The excluded volume effect between a pair of particles or between a particle and the boundary is modeled by a repulsive potential force. The drag exerted to the fluid by a particle is assumed proportional to its velocity. When the particle is rigid, its state is described by a zero velocity gradient tensor within the nonzero phase field that defines its profile and a constraining stress exists therein. While the particle is elastic, a linear constitutive equation for the elastic stress is provided within the particle domain. A hybrid, thermodynamically consistent hydrodynamic model valid in the entire computational domain is then derived for the fluid-particle ensemble using the generalized Onsager principle accounting for both rigid and elastic particles. Structure-preserving numerical algorithms are subsequently developed for the thermodynamically consistent model. numerical tests in 2D and 3D space are carried out to verify the rate of convergence and numerical examples are given to demonstrate the usefulness of the computational framework for simulating fluid-structure interactions for passive as well as self-propelling active particles in a viscous fluid matrix. Copyright © 2021, The Authors. All rights reserved.

关键词： Hydrodynamics

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B(s) → ηc(P, V) decays and effects of the next-to-leading order contributions in the perturbative QCD approach

arXiv

引用

arXiv 2019年

作者： Xiao, Zhen-Jun Yan, Da-Cheng Liu, Xin Department of Physics Institute of Theoretical Physics Nanjing Normal University Nanjing Jiangsu210023 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu210023 China School of Mathematics and Physics Changzhou University Changzhou213164 China Department of Physics Jiangsu Normal University Xuzhou221116 China

By employing the perturbative QCD (PQCD) factorization approach, we studied the sixteen B/Bs → ηc(π, K, η(′), ρ, K∗, ω, φ) decays with the inclusion of the currently known next-to-leading order (NLO) contributions. We found the following main points: (a) for the five measured B → ηc(K, K∗) and Bs → ηcφ decays, the NLO contributions can provide (80 − 180)% enhancements to the leading order (LO) PQCD predictions of their branching ratios, which play an important role to help us to interpret the data;(b) for the seven ratios R1,···,7 of the branching ratios defined among the properly selected pair of the considered decay modes, the PQCD predictions for the values of R3,4,5 agree well with those currently available BaBar and Belle measurements;(c) for B0 → ηcKS0 decay, the PQCD predictions for both the direct and mixing induced CP asymmetries do agree very well with the measured values within errors;and (d) the PQCD predictions for ratios R1,2 and R6,7 also agree with the general expectations and will be tested by the future experiments. Copyright © 2019, The Authors. All rights reserved.

关键词： Forecasting

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Hidden-charm tetraquarks with strangeness in the chiral quark model

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Physical Review D 2021年第9期104卷 094035-094035页

作者： Gang Yang Jialun Ping Jorge Segovia Department of Physics Zhejiang Normal University Jinhua 321004 China Department of Physics and Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 People’s Republic of China Departamento de Sistemas Físicos Químicos y Naturales Universidad Pablo de Olavide E-41013 Sevilla Spain

The hidden-charm tetraquarks with strangeness, cc¯sq¯ (q=u, d), in JP=0+, 1+, and 2+ are systematically investigated in the framework of real- and complex-scaling range of a chiral quark model, whose parameters have been fixed in advance describing hadron, hadron-hadron, and multiquark phenomenology. Each tetraquark configuration, compatible with the quantum numbers studied, is taken into account; this includes meson-meson, diquark-antidiquark, and K-type arrangements of quarks with all possible color wave functions in the four-body sector. Among the different numerical techniques to solve the Schrödinger-like four-body bound state equation, we use a variational method in which the trial wave function is expanded in complex-range Gaussian basis functions, which is characterized by its simplicity and flexibility. This theoretical framework has already been used to study different kinds of multiquark systems, such as the hidden-charm pentaquarks Pc+ and doubly charmed tetraquarks Tcc+. The recently reported Zcs states by the BESIII and LHCb Collaborations could be associated, in our investigation, with either compact tetraquark or hadronic molecular resonance configurations. However, it is fair to recognize that our complex poles survive when either the (cc¯)(sq¯) or (cq¯)(sc¯) configuration is preserved, but most of them get diluted when both are considered at the same time, indicating that such states seem to be very unstable. Finally, we mention that similar types of structures are also found in the mass range between 3.8 and 4.6 GeV.

关键词： Many-body techniques Quantum chromodynamics Quark model Strong interaction

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Bottomoniumlike tetraquarks in a chiral quark model

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Physical Review D 2022年第1期106卷 014021-014021页

The low-lying bottomoniumlike tetraquarks bb¯qq¯ (q=u, d, s) with spin-parity JP=0+, 1+, and 2+, and isospin I=0, 1, or 12, are systematically investigated within the theoretical framework of real- and complex-scaling range of a chiral quark model, which has already been successfully applied in analysis of several multiquark systems. A complete four-body S-wave function, which includes meson-meson, diquark-antidiquark and K-type arrangements of quarks, along with all possible color configurations are considered. In the bb¯qq¯ (q=u, d) tetraquark system, we found resonance states of B(*)B¯(*), ϒω, ϒρ, and ηbρ nature with all possible I(JP) quantum numbers. Their masses are generally located in the energy range 11.0–11.3 GeV and their widths are less than 10 MeV. In addition, extremely narrow resonances, with two-meson strong decay widths less than 1.5 MeV, are obtained in both bb¯us¯ and bb¯ss¯ tetraquark systems. Particularly, four radial excitations of ϒK* and ηbK* are found at ∼11.1 GeV in JP=0+, 1+, and 2+ channels of bb¯us¯ system. One ϒ(1S)ϕ(2S) resonance state is obtained at 11.28 GeV in the JP=1+ sector.

关键词： Quantum chromodynamics Quark model Strong interaction

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Arbitrarily high-order structure-preserving schemes for the Gross-Pitaevskii equation with angular momentum rotation in three dimensions

arXiv

引用

arXiv 2020年

作者： Cui, Jin Wang, Yushun Jiang, Chaolong Department of Basic Sciences Nanjing Vocational College of Information Technology Nanjing210023 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Mathematical Sciences Nanjing Normal University Nanjing210023 China School of Statistics and Mathematics Yunnan University of Finance and Economics Kunming650221 China

In this paper, we design a novel class of arbitrarily high-order structure-preserving numerical schemes for the time-dependent Gross-Pitaevskii equation with angular momentum rotation in three dimensions. Based on the idea of the scalar auxiliary variable approach which is proposed in the recent papers [J. Comput. Phys., 416 (2018) 353-407 and SIAM Rev., 61(2019) 474-506] for developing energy stable schemes for gradient flow systems, we firstly reformulate the Gross-Pitaevskii equation into an equivalent system with a modified energy conservation law. The reformulated system is then discretized by the Gauss collocation method in time and the standard Fourier pseudo-spectral method in space, respectively. We show that the proposed schemes can preserve the discrete mass and modified energy exactly. numerical results are addressed to verify the efficiency and high-order accuracy of the proposed schemes. Copyright © 2020, The Authors. All rights reserved.

关键词： Bose-Einstein condensation

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Rho-pion transition form factors in the kT factorization formulism revisited

arXiv

引用

arXiv 2018年

作者： Hua, Jun Cheng, Shan Zhang, Ya-Lan Xiao, Zhen-Jun Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing Jiangsu210023 China School of Physics and Microelectronics Science Hunan University Changsha Hunan410082 China Department of Faculty of Mathematics and Physics Huaiyin Institute of Technology Huaian Jiangsu223001 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu210023 China

We revisit the evaluations for the spacelike and timelike ρπ transition form factors Fρπ(Q2) and Gρπ(Q2) with the inclusion of the the next-to-leading order (NLO) QCD contributions in the framework of the kT factorization theorem. The infrared divergence is regularized by the transversal momentum carried by external valence quarks, and ultimately absorbed into the meson wave functions. In the region of Q2 6 2 GeV2, where PQCD factorization apporach applicable, the NLO contribution can bring no larger than 35% enhancement to the spacelike form factor Fρπ(Q2). For the timelike form factor derived under the kinematic exchanging symmetry, this contribution is also under control when the momentum transfer squared is large enough. We also prolong our prediction into the small Q2 region by taking the Lattice QCD results into account, and subsequently obtain the coupling gρπγ = Gρπ(0) = 0.596. Copyright © 2018, The Authors. All rights reserved.

关键词： Approximation theory

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NLO twist-3 contributions to B→π form factors in kT factorization

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Physical Review D 2014年第9期89卷 094004-094004页

作者： Shan Cheng Ying-Ying Fan Xin Yu Cai-Dian Lü Zhen-Jun Xiao Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing Jiangsu 210023 People’s Republic of China Institute of High Energy Physics and Theoretical Physics Center for Science Facilities Chinese Academy of Sciences Beijing 100049 People’s Republic of China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 People’s Republic of China

In this paper, we calculate the next-to-leading-order (NLO) twist-3 contribution to the form factors of B→π transitions by employing the kT factorization theorem. All the infrared divergences regulated by the logarithms ln(kiT2) cancel between those from the quark diagrams and from the effective diagrams for the initial B meson wave function and the final pion meson wave function. An infrared finite NLO hard kernel is, therefore, obtained, which confirms the application of the kT factorization theorem to the B meson semileptonic decays at the twist-3 level. From our analytical and numerical evaluations, we find that the NLO twist-3 contributions to the form factors f+,0(q2) of the B→π transition are similar in size but have an opposite sign with the NLO twist-2 contribution, which leads to a large cancellation between these two NLO parts. For the case of f+(0), for example, the 24% NLO twist-2 enhancement to the full LO prediction is largely canceled by the negative (about −17%) NLO twist-3 contribution, leaving a small and stable 7% enhancement to the full LO prediction in the whole range of 0≤q2≤12 GeV2. At the full NLO level, the perturbative QCD prediction is FB→π(0)=0.269−0.050+0.054. We also study the possible effects on the perturbative QCD predictions when different sets of the B meson and pion distribution amplitudes are used in the numerical evaluation.

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A Distributed Approximation Algorithm for the Total Dominating Set Problem 1

引用

18th International Conference on Algorithmic Aspects in Information and Management, AAIM 2024

作者： Wang, Limin Zhang, Zhao Du, Donglei Mao, Yaping Zhang, Xiaoyan School of Mathematical Sciences Henan Institute of Science and Technology Xinxiang453003 China College of Mathematics and Computer Sciences Zhejiang Normal University Zhejiang321004 China Faculty of Management University of New Brunswick Fredericton E3B 5A3 New Brunswick Canada School of Mathematics and Statistics Qinghai Normal University Qinghai810008 China Academy of Plateau Science and Sustainability Xining Qinghai810008 China School of Mathematical Science and Institute of Mathematics Key Laboratory of Ministry of Education Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Jiangsu210023 China

ISBN: (数字)9789819777983

ISBN: (纸本)9789819777976

Given a network graph G=(V,E), a subset T⊆V is said to be a total dominating set (TDS) if every v∈V is adjacent to at least one node in T. In this paper, we present a distributed algorithm for the TDS problem via the LP relaxation techniques. For a positive integer k and maximum degree Δ, the proposed algorithm outputs a fractional total dominating set of expected size O(kΔ2k)|TDSOPT|. The distributed algorithm runs in O(k2) communication rounds, and the algorithm use messages of size O(logΔ). The fractional solution is then rounded to obtain an integer total dominating set for the original problem. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： Consensus algorithm

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Double-heavy tetraquarks

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Physical Review D 2020年第1期101卷 014001-014001页

作者： Gang Yang Jialun Ping Jorge Segovia Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics Tsinghua University Beijing 100084 People’s Republic of China Department of Physics and Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 People’s Republic of China Departamento de Sistemas Físicos Químicos y Naturales Universidad Pablo de Olavide E-41013 Sevilla Spain

In the framework of the chiral quark model along with complex scaling range, we perform a dynamical study on the low-lying S-wave double-heavy tetraquark states (QQq¯q¯, Q=c, b and q=u, d) with an accurate computing approach, Gaussian expansion method. The meson-meson and diquark-antidiquark configurations within all possible color structures for spin-parity quantum numbers JP=0+, 1+, and 2+ and in the 0 and 1 isospin sectors are considered. Possible tightly bound and narrow resonance states are obtained for double-charm and double-bottom tetraquarks with IJP=01+, and these exotic states are also obtained in charm-bottom tetraquarks with 00+ and 01+ quantum numbers. Only a loosely bound state is found in charm-bottom tetraquarks of 02+ states. All of these bound states within meson-meson configurations are loosely bound whether in color-singlet channels or coupling to hidden-color ones. However, compact structures are available in diquark-antidiquark channels except for charm-bottom tetraquarks in 02+ states.

关键词： Hadron mixing Hadron-hadron interactions Quark mixing Quark model Heavy mesons Mass Parity Spin

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Charmoniumlike tetraquarks in a chiral quark model

arXiv

引用

arXiv 2023年

作者： Yang, Gang Ping, Jialun Segovia, Jorge Department of Physics Zhejiang Normal University Jinhua321004 China Department of Physics Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China Departamento de Sistemas Físicos Químicos y Naturales Universidad Pablo de Olavide SevillaE-41013 Spain

The lowest-lying charmonium-like tetraquarks (Equation presented) (q = u, d) and (Equation presented), with spin-parity JP = 0+, 1+ and 2+, and isospin I = 0 and 1, are systematically investigated within the theoretical framework of complex-scaling range for a chiral quark model that has already been successfully applied in former studies of various tetra- and penta-quark systems. A four-body S-wave configuration which includes meson-meson, diquark-antidiquark and K-type arrangements of quarks, along with all possible color wave functions, is comprehensively considered. Several narrow resonances are obtained in each tetraquark channel when a fully coupled-channel computation is performed. We tentatively assign theoretical states to experimentally reported charmonium-like signals such as X(3872), Zc(3900), X(3960), X(4350), X(4685) and X(4700). They can be well identified as hadronic molecules;however, other exotic components which involve, for instance, hidden-color channels or diquark-antidiquark structures play a considerable role. Meanwhile, two resonances are obtained at 4.04 GeV and 4.14 GeV which may be compatible with experimental data in the energy interval 4.0−4.2 GeV. Furthermore, the X(3940) and X(4630) may be identified as color compact tetraquark resonances. Finally, we also find few resonance states in the energy interval from 4.5 GeV to 5.0 GeV, which would be awaiting for discovery in future experiments. Copyright © 2023, The Authors. All rights reserved.

关键词： Germanium alloys

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