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Y(4626) in a chiral constituent quark model

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Physical Review D 2020年第5期101卷 054010-054010页

作者： Yue Tan Jialun Ping 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

Recently, the Belle Collaboration reported a new exotic state Y(4620) with mass at 4625.9 MeV in the positronium annihilation process. Inspired by experiment, we study the tetraquark system cs¯sc¯ with quantum numbers JP=1− in the framework of chiral constituent quark model with the help of Gaussian expansion method. Two structures, diquark-antidiquark and meson-meson, with all possible color and spin configurations are considered. The result shows that no bound state can be formed. To investigate the possible resonance states, the real scaling method is employed. Several resonance states with energies 4354, 4408, 4469, 4497, and 4531 MeV are proposed. Taking into account the errors in calculating the qq¯ mesons, the system errors in the calculation of four-quark system are around 60–100 MeV. The resonance with energy 4531 MeV is possible the candidate of the newly found state Y(4620).

关键词： Hadron-hadron interactions Quark model

Investigation of qqqsq¯ pentaquarks in a chiral quark model

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arXiv 2020年

作者： Qin, Liting Tan, Yue Hu, Xiaohuang Ping, Jialun Department of Physics Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China

We investigate the pentaquark system qqqsq¯in a framework of chiral quark model. Two structures, (qqq)(sq¯) and (qqs)(qq¯), with all possible color, spin, flavor configurations are considered. The calculations show that there are several possible resonance states, Sigmaπ and NK¯ state with IJP = 012−, Σ∗π with IJP = 032−, Σ∗ρ with IJP = 025 −, ∆K¯ with IJP = 132− and ∆K¯ ∗ with IJP = 152−. Where the NK¯ state with IJP = 012− can be used to explain the Λ(1405), and together with another state Σπ is related to the two-pole structure of the scattering amplitude proposed before. The decay properties of Λ(1520) prevent the assignment of Σ∗π with IJP = 023 − to Λ(1520), although the energy ∼ 1518 MeV of Σ∗π is close to experimental value of Λ(1520). Other resonance states generally have a large width. Copyright © 2020, The Authors. All rights reserved.

关键词： Hadrons

Investigation of Ξc0 in a chiral quark model

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arXiv 2020年

作者： Hu, Xiaohuang Tan, Yue Ping, Jialun Department of Physics Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China

Recently, three new states of Ξc0 were observed in the invariant mass spectrum of Λ+c K− by LHCb collaboration. In this work, we use a chiral quark model to investigate these three exited states with the help of Gaussian expansion method both in three-quark structure and in five-quark structure with all possible quantum numbers (formula presented). The calculations shows that the 2S states of Ξc′(2579)0 and Ξc(2645)0 are comparable to experimental results;In addition, the resonance states of five-quark configuration are possible candidates of these new states with negative parity by using the real scaling method and their decay width are also given. Copyright © 2020, The Authors. All rights reserved.

关键词： Elementary particles

numerical Validations of the Tangent Linear Model for the Lorenz Equations

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Computer Modeling in Engineering & Sciences 2019年第7期120卷 83-104页

作者： Tengjin Zhao Jing Zhang Zhilin Li Zhiyue Zhang School of Mathematical Sciences Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex SystemsNanjing Normal UniversityNanjing210023China Department of Mathematics North Carolina State UniversityRaleighNC 27695-8205USA

The validity of the tangent linear model(TLM)is studied numerically using the example of the Lorenz equations in this *** relationship between the limit of the validity time of the TLM and initial perturbations for the Lorenz equations is investigated using the Monte Carlo sampling method.A new error function between the nonlinear and the linear evolution of the perturbations is ***,numerical sensitivity analysis is carried to establish the relationship between parameters and the validity of the TLM,such as the initial perturbation,the prediction time,the time step size and so on,by the method of mathematical statistics.

关键词： Lorenz model tangent linear model nonlinear model Monte Carlo

QQqq in a chiral constituent quark model

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arXiv 2020年

作者： Tan, Yue Lu, Weichang Ping, Jialun Dept. of Physics and Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China

Inspired by Ξccreported by LHCb Collaboration and X(5568) reported by D0 Collaboration, the QQqq (Q = c, b, q = u, d) tetraquark states, are studied in the present work. With the help of Gaussian expansion method, two structures, diquark-antiquark and meson-meson, with all possible color configurations are investigated systematically in a chiral quark model to search for the possible stable states. The results show that there is no bound state in the isovector QQqq system, while there are rather deep bound states in the isoscalar bbqq, ccqq and bcqq systems. Mixing two structures of diquark-antidiquark and meson-meson can introduce more attractions and convert some unbound isoscalar states into shallow bound states. The large mass of the heavy quark is beneficial to the formation of the bound state. The separations between quarks are calculated to unravel the spacial structure of the system. Copyright © 2020, The Authors. All rights reserved.

关键词： Hadrons

Triply heavy baryons in the constituent quark model

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Chinese Physics C 2020年第2期44卷 33-41页

作者： Gang Yang Jialun Ping Pablo GOrtega Jorge Segovia Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics Tsinghua UniversityBeijing 100084China Department of Physics and Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal UniversityNanjing 210023China Grupo de Física Nuclear and Instituto Universitario de Física Fundamental y Matemáticas(IUFFyM) Universidad de SalamancaE-37008 SalamancaSpain Departamento de Sistemas Físicos Químicos y NaturalesUniversidad Pablo de OlavideE-41013 SevillaSpain

The constituent quark model is used to compute the ground and excited state masses of QQQ baryons containing either c or b *** quark model parameters previously used to describe the properties of charmonium and bottomonium states were used in this *** non-relativistic three-body bound state problem is solved by means of the Gaussian expansion method which provides sufficient accuracy and simplifies the subsequent evaluation of the matrix *** low-lying states with quantum numbers J^P=1/2^±,3/2^±,5/2^±and 7/2^+are *** compare the results with those obtained by the other theoretical *** is a general agreement for the mass of the ground state in each sector of triply heavy ***,the situation is more puzzling for the excited states,and appropriate comments about the most relevant features of our comparison are given.

关键词： Quantum Chromodynamics quark models properties of baryons exotic baryons

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

Calibration and Modelling of Vegetation Structure Parameter B for L-Meb Models Over Agricultural Sites

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SSRN

SSRN 2024年

作者： Zhang, Hui Wang, Hongquan Sun, Zhibin Gao, Lun Wang, Yixiang Tong, Cheng Zhu, Luyao Shi, Zhou Institute of Agricultural Remote Sensing and Information Technology Application College of Environmental and Resource Sciences Zhejiang University Hangzhou310058 China Agriculture and Agri-Food Canada Lethbridge Research and Development Centre LethbridgeAB Canada Jiangsu Key Laboratory for Numerical Simulation of Large-Scale Complex Systems Nanjing Normal University Nanjing210023 China Agroecosystem Sustainability Center Institute for Sustainability Energy and Environment the University of Illinois at Urbana-Champaign UrbanaIL61801 United States State Key Laboratory of Subtropical Silviculture Zhejiang A&F University Hangzhou311300 China Key Laboratory of Carbon Cycling in Forest Ecosystems and Carbon Sequestration of Zhejiang Province Zhejiang A&F University Hangzhou311300 China College of Environment and Resource Sciences Zhejiang A&F University Lin’an Zhejiang311300 China Research Institute for Urban Planning and Sustainability Hangzhou City University Hangzhou310015 China Key Laboratory of Spectroscopy Sensing Ministry of Agriculture Hangzhou310058 China

Passive microwave observations of vegetation water content (VWC) are important to monitor vegetation growth status and terrestrial aboveground biomass. To constrain the L-band Microwave Emission of the Biosphere (L-MEB) model for NASA’s Soil Moisture Active Passive (SMAP) satellite mission, vegetation structure parameter b is often used to estimate VWC from the climatological Normalized Difference Vegetation Index (NDVI). However, little is known about what and how the driving factors impact the parameter b and its modeling due to the lack of quantitative analysis. Based on the Passive Active L-band Sensor (PALS) data from the SMAPVEX16-MB campaign, this study firstly calibrated the parameter b for canola, wheat and soybean. Afterwards, a Random Forest algorithm was employed to model b-values using both h and v polarized observations with the input features screened by correlation analysis and stepwise regression for each vegetation type, the R2 of which exceeds 82%. Considering the poor interpretability of machine learning algorithms, we also employed multivariable-linear regression to quantify their influence on b-values and achieved an R2 exceeding 75%. The results showed all three crop types had an increasing trend in b-values at dual-polarization with their growth, except for wheat which exhibited a decreasing trend at v-polarization. Among the three crops, wheat and soybean indicated sharp changes in b-values, particularly during the late growth stage, while canola exhibited slower changes. The b-values were higher at v-polarization than at h-polarization, except for wheat during the early growth stage and at the end of the late growth stage. The results of multivariable regression with vegetation type as dummy variables (soybean as the control) indicated that crop type significantly affected b values, with canola and wheat exhibiting positive effects on b-values at h-polarization but negative effects at v-polarization. Additionally, we found that VWC, biomass

关键词： Polarization

Study of Bs→ φ+-decays in the PQCD factorization approach with lattice QCD input

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arXiv 2020年

作者： Jin, Su-Ping Xiao, Zhen-Jun Department of Physics and Institute of Theoretical Physics Nanjing Normal University Jiangsu Nanjing210023 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China

In this paper, we studied systematically the semileptonic decays Bs→ φl+l-with l-= (e-, μ-, τ-) by using the perturbative QCD (PQCD) and the "PQCD+Lattice" factorization approach, respectively. We first evaluated all relevant form factors Fi(q2) in the low q2region using the PQCD approach, and we also took the available lattice QCD results at the high-q2region as additional input to improve the extrapolation of Fi(q2) from the low-q2region to the endpoint qmax2. We then calculated the branching ratios and many other physical observables: AFBl, FLφ, S3,4,7, A5,6,8,9and the clean angular observables P1,2,3and P'4,5,6,8. From our studies, we find the following points: (a) the PQCD and "PQCD+Lattice" predictions of B(Bs→ φμ+μ-) are about 7×10-7, which agree well with the LHCb measured values and the QCD sum rule prediction within still large errors;(b) we defined and calculated the ratios of the branching ratios Rφeμand Rφμτ;(c) the PQCD and "PQCD+Lattice" predictions of the longitudinal polarization FL, the CP averaged angular coefficients S3,4,7and the CP asymmetry angular coefficients A5,6,8,9, agree with the LHCb measurements in all considered bins within the still large experimental errors;and (d) for those currently still unknown observables Rφeμ,Rφμτ,AFBl, P1,2,3and P'4,5,6,8, we suggest LHCb and Belle-II Collaboration to measure them in their experiments. © 2020, CC BY.

关键词： Quantum theory