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Study of Bs←φ+- Decays in the PQCD Factorization Approach with Lattice QCD Input

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Advances in High Energy Physics 2021年 2021卷

作者： Jin, Su-Ping Xiao, Zhen-Jun Department of Physics and Institute of Theoretical Physics Nanjing Normal University NanjingJiangsu210023 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 Fiq2 in the low-q2 region using the PQCD approach, and we also took the available lattice QCD results at the high-q2 region as additional input to improve the extrapolation of Fiq2 from the low-q2 region to the endpoint qmax2. We then calculated the branching ratios and many other physical observables AFBl, FLφ, S3,4,7, and A5,6,8,9 and the clean angular observables P1,2,3 and P4,5,6,8′. From our studies, we find the following points: (a) the PQCD and "PQCD+Lattice"predictions of BBs←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 Rφeμ and Rφμτ;(c) the PQCD and "PQCD+Lattice"predictions of the longitudinal polarization FL, the CP-averaged angular coefficients S3,4,7, and 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,P1,2,3, and P4,5,6,8′, we suggest LHCb and Belle-II Collaboration to measure them in their experiments. © 2021 Su-Ping Jin and Zhen-Jun Xiao.

关键词： Forecasting

Reanalysis of the most strange dibaryon within constituent quark models

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arXiv 2019年

作者： Huang, Hongxia Zhu, Xinmei Ping, Jialun Department of Physics Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China Department of Physics Yangzhou University Yangzhou225009 China

The most strange dibaryon ΩΩ with quantum numbers S = −6, I = 0, and JP = 0+, 1−, 2+, 3− is reanalyzed in the framework of quark delocalization color screening model (QDCSM) and chiral quark model (ChQM). The ΩΩ dibaryon with JP = 0+ is bound, and the one with other quantum numbers JP = 1−, 2+, 3− are all unbound in our calculation. The low-energy scattering phase shifts, the scattering length, and the effective range of the ΩΩ dibaryon with JP = 0+ also support the existence of such strange dibaryon. This dibaryon is showed to be a shallow bound state in QDCSM, while the binding energy becomes much larger in the ChQM by including the effect of the hidden-color channel coupling. And the scalar nonet meson-exchange in the ChQM also provides more attraction for the ΩΩ system. Experimental search for such most strange dibaryon will provide much information for understanding the hadron-hadron interactions in different quark models. Copyright © 2019, The Authors. All rights reserved.

关键词： Quantum theory

Search for doubly-heavy dibaryons in the quark-delocalization color-screening model

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arXiv 2021年

作者： Xia, Zhuocheng Fan, Saijun Zhu, Xinmei Huang, Hongxia Ping, Jialun Department of Physics Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China Department of Physics Yangzhou University Yangzhou225009 China

We perform a systemical investigation of the low-lying doubly-heavy dibaryon systems with strange S = 0, isospin I = 0, 1, 2 and the angular momentum J = 0, 1, 2, 3 in the quark de- localization color screening model. We find the effect of channel-coupling cannot be neglected in the study of the multi-quark systems. Due to the heavy flavor symmetry, the results of the doubly- charm and doubly-bottom dibaryon systems are similar with each other. Both of them have three bound states, the quantum numbers of which are IJ = 00, IJ = 02 and IJ = 13, respectively. The energies are 4554 MeV, 4741 MeV, and 4969 MeV respectively for the doubly-charm systems and 11219 MeV, 11416 MeV, and 11633 MeV respectively for the doubly-bottom dibaryon systems. Besides, six resonance states are obtained, which are IJ = 00 NΞccand NΞbbwith resonance mass of 4716 MeV and 11411 MeV respectively, IJ = 11 NΞ∗ccand NΞ∗bbwith resonance mass of 4757 MeV and 11432 MeV respectively, and IJ = 12 ΣcΣ∗cand ΣbΣ∗bwith resonance mass of 4949 MeV and 11626 MeV respectively. All these heavy dibaryons are worth searching for on experiments, although it will be a challenging work. © 2021, CC BY.

关键词： Resonance

Is d∗(2380) a compact hexaquark state?

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arXiv 2023年

作者： Pan, Manying Zhu, Xinmei Ping, Jialun Department of Physics Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China Department of Physics Yangzhou University Yangzhou225009 China

The most fascinating dibaryon in the non-strange quark sector is d∗(2380), which was reported by WASA-at-COSY Collaboration and confirmed by A2@MAMI Collaboration. The reported mass and decay width are M ≈ 2.37 GeV, Γ ≈ 70 MeV and the quantum numbers are IJP = 03+. The structure of d∗(2380) is still in controversy. In the present calculation, the powerful method in few-body system, Gaussian Expansion Method (GEM) is employed to explore the structure of d∗(2380) in the framework of constituent quark models without assuming the presupposed structure. The results show that the radius of d∗(2380) is around 0.8 fm, it is a very compact object. Because of the compact structure, the color singlet-singlet component has a large overlap with the color octet-octet one, two colorless, large overlapped ∆s dominate the state is possible. Copyright © 2023, The Authors. All rights reserved.

关键词： Color

A novel class of energy-preserving Runge-Kutta methods for the Korteweg-de Vries equation

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arXiv 2021年

作者： Chen, Yue Gong, Yuezheng Hong, Qi Wang, Chunwu Department of Mathematics Nanjing University of Aeronautics and Astronautics Nanjing211106 China MIIT Nanjing211106 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing210023 China

In this paper, we present a quadratic auxiliary variable approach to develop a new class of energy-preserving Runge-Kutta methods for the Korteweg-de Vries equation. The quadratic auxiliary variable approach is first proposed to reformulate the original model into an equivalent system, which transforms the energy conservation law of the Korteweg-de Vries equation into two quadratic invariants of the reformulated system. Then the symplectic Runge-Kutta methods are directly employed for the reformulated model to arrive at a new kind of time semi-discrete schemes for the original problem. Under the consistent initial condition, the proposed methods are rigorously proved to maintain the original energy conservation law of the Korteweg-de Vries equation. In addition, the Fourier pseudo-spectral method is used for spatial discretization, resulting in fully discrete energy-preserving schemes. To implement the proposed methods effectively, we present a very efficient iterative technique, which not only greatly saves the calculation cost, but also achieves the purpose of practically preserving structure. Ample numerical results are addressed to confirm the expected order of accuracy, conservative property and efficiency of the proposed algorithms. Copyright © 2021, The Authors. All rights reserved.

关键词： Runge Kutta methods

Investigating the excited ω 0 c states through c K and c K decay channels

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arXiv 2017年

作者： Huang, Hongxia Ping, Jialun Wang, Fan Dept. of Physics and Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China Department of Physics Nanjing University Nanjing210093 China

Inspired by the five newly observed ω 0 c states by the LHCb detector, we study the ω 0 c states as the Swave molecular pentaquarks with I = 0, JP = 1 2 , 3 2 , and 5 2 by solving the RGM equation in the framework of chiral quark model. Both the energies and the decay widths are obtained in this work. Our results suggest that c(3119)0 can be explained as an Swave resonance state of D with JP = 1 2 , and the decay channels are the Swave cK and cK . Other reported ω 0 c states cannot be obtained in our present calculation. Another ω 0 c state with much higher mass 3533 MeV with JP = 5 2 is also obtained. In addition, the calculation is extended to the 0 b states, similar results as that of ω 0 c are obtained. Copyright © 2017, The Authors. All rights reserved.

关键词： Hadrons

Topological properties and localization transition in a one-dimensional non-Hermitian lattice with a slowly varying potential

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Physical Review B 2022年第10期105卷 104201-104201页

作者： Siqing Li Mengyao Li Yi Gao Peiqing Tong Center for Quantum Transport and Thermal Energy Science Jiangsu Key Laboratory on Opto-Electronic Technology School of Physics and Technology Nanjing Normal University Nanjing 210023 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Physics and Technology Nanjing Normal University Nanjing 210023 China

We explore the eigenenergy distribution, localization transition, and topological property of a one-dimensional non-Hermitian lattice with a slowly varying potential, which does not possess parity-time (PT) symmetry. We found that, in contrast to PT-symmetric systems whose eigenenergies can stay real until the PT-symmetry breaking point, the eigenenergies in the present system are fully complex and their distribution in the complex plane depends on the parameters. As non-Hermiticity is introduced into the system, also depending on the parameters, the eigenstates may show a crossover behavior from fully extended to fully localized as non-Hermiticity is increased, or there will be a sharp localization transition at finite non-Hermiticity. Nevertheless, this non-Hermitian system is proven to be topologically trivial, thus we conclude that in general non-Hermitian systems, the localization transition is not always of a topological nature.

关键词： Anderson localization Topological phase transition Non-Hermitean systems PT-symmetry

Exploring dynamical phase transitions in the XY chain through a linear quench: Early and long-term perspectives

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Physical Review A 2024年第4期110卷 042209页

作者： Kaiyuan Cao Hongsheng Hou Peiqing Tong School of Physics Hangzhou Normal University Hangzhou 311121 China Department of Physics Institute of Theoretical Physics Nanjing Normal University Nanjing 210023 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 China

We investigate the nonequilibrium dynamics induced by a finite-time linear quench in the XY chain. Initially, we examine the dynamical quantum phase transition (DQPT-LE), characterized by the nonanalytic behavior of the Loschmidt amplitude. We find distinct behaviors of DQPT-LEs during and following the ramp. Following the ramp, the ramp crossing the critical point hc is the sufficient condition for the occurrence of DQPT-LE, but it is not during the ramp. Through adiabatic-impulse-adiabatic (AIA) approximation analysis, we establish that adequate distancing from the critical point is crucial for DQPT-LE manifestation during the ramp, elucidating the absence of DQPT-LE as the ramp gets faster. Additionally, we explore another type of dynamical phase transition (DQPT-OP), describing the long-term relaxation behavior of the order parameter. Our finding indicates that the asymptotic behavior of the time-dependent part induced by the linear quench is equivalent to that following a sudden quench, i.e., the time-dependent part exhibits power-law decays of ∼t−3/2 and ∼t−1/2 for the ramp to the commensurate and incommensurate phases, respectively. Moreover, we also delve into the steady part, which showcases nonanalytic singularities at the critical point.

关键词： Dynamical phase transitions Nonequilibrium statistical mechanics XY model

Search for doubly heavy dibaryons in the quark delocalization color screening model

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Physical Review C 2022年第2期105卷 025201-025201页

作者： Zhuocheng Xia Saijun Fan Xinmei Zhu Hongxia Huang 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 Department of Physics Yangzhou University Yangzhou 225009 People's Republic of China

We perform a systemical investigation of the low-lying doubly heavy dibaryon systems with strange S=0, isospin I=0, 1, 2, and the angular momentum J=0, 1, 2, 3 in the quark delocalization color screening model. We find the effect of channel-coupling cannot be neglected in the study of the multi-quark systems. Several bound systems are obtained. They are the doubly charm dibaryon systems with IJ=00, IJ=01, and IJ=02, and the corresponding energies are 4590, 4720, and 4764 MeV, respectively; and the doubly bottom dibaryon systems with IJ=00, IJ=02, and IJ=13, and the corresponding energies are 11219, 11416, and 11633 MeV, respectively. Besides, six resonance states are obtained, which are IJ=00NΞcc and NΞbb with resonance masses of 4730 and 11411 MeV respectively, IJ=11NΞcc* and NΞbb* with resonance masses of 4775 and 11432 MeV respectively, and IJ=12ΣcΣc* and ΣbΣb* with resonance masses of 4935 and 11626 MeV respectively. All these heavy dibaryons are worth searching for in experiments, although it will be a challenging work.

关键词： Cluster models Particle interactions Quark model Heavy baryons