Inspired by the recent observation of exotic resonances X(4140), X(4274), X(4350), X(4500), and X(4700) reported by several experiment collaborations, we investigated the four-quark system csc¯s¯ with quantu...
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Inspired by the recent observation of exotic resonances X(4140), X(4274), X(4350), X(4500), and X(4700) reported by several experiment collaborations, we investigated the four-quark system csc¯s¯ with quantum numbers JPC=1++ and 0++ in the framework of the chiral quark model. Two configurations, diquark-antidiquark and meson-meson, with all possible color structures are considered. The results show that no molecular state can be formed, but the resonance may exist if the color structure of the meson-meson configuration is 8⊗8. In the present calculation, the X(4274) can be assigned as the csc¯s¯ tetraquark states with JPC=1++, but the energy of X(4140) is too low to be regarded as the tetraquark state. X(4350) can be a good candidate of the compact tetraquark state with JPC=0++. When the radial excitation is taken into account, the X(4700) can be explained as the 2S radial excited tetraquark state with JPC=0++. As for X(4500), there is no matching state in our calculation.
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 calc...
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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, Σπ and NK¯ state with IJP=012−, Σ*π with IJP=032−, Σ*ρ with IJP=052−, ΔK¯ with IJP=132−, and ΔK¯* 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=032− to Λ(1520), although the energy ≈1518MeV of Σ*π is close to experimental value of Λ(1520). Other resonance states generally have a large width.
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 quant...
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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).
In this paper we calculate the mass and probability fractions of the meson-meson components of X(3872) in an unquenched quark model. Different from most other unquenched quark models, the quark-pair creation operator ...
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In this paper we calculate the mass and probability fractions of the meson-meson components of X(3872) in an unquenched quark model. Different from most other unquenched quark models, the quark-pair creation operator from P03 is modified by considering the effects of the created quark pair’s energy and the separation between the created quark pair and the valence quark pair. In the calculation all of the wave functions of the mesons and the relative motion between two mesons are obtained by solving the corresponding Schrödinger equation with the help of the Gaussian expansion method. The multichannel couplings of the quark-antiquark state with possible meson-meson states are calculated. The results show that X(3872) can be described as a mixing state of the dominant charmonium state (70%) and meson-meson components (30%).
This paper is concerned with a mutualism ecological model with stochastic perturba- tions. The local existence and uniqueness of a positive solution are obtained with positive initial value, and the asymptotic behavio...
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This paper is concerned with a mutualism ecological model with stochastic perturba- tions. The local existence and uniqueness of a positive solution are obtained with positive initial value, and the asymptotic behavior to the problem is studied. Moreover, we show that the solution is stochastically bounded, uniformly continuous and stochastic perma- nence. The sufficient conditions for the system to be extinct are given and the conditionsfor the system to be persistent are also established. At last, some figures are presented to illustrate our main results.
Inspired by the updated information on Ω(2012) by the Belle Collaboration, we conduct a study of all possible S-wave pentaquark systems with quark contents sssqq¯,q=u, d in a chiral quark model with the help of ...
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Inspired by the updated information on Ω(2012) by the Belle Collaboration, we conduct a study of all possible S-wave pentaquark systems with quark contents sssqq¯,q=u, d in a chiral quark model with the help of Gaussian expansion method. Channel coupling is also considered. The real-scaling method (stabilization method) is employed to identify and check the bound states and the genuine resonances. In addition, the decay widths of all resonances are given. The results show that Ω(2012) can be interpreted as a Ξ*K¯ molecular state with quantum number of IJP=0(32)−. Another bound state Ωπ with IJP=1(32)− is also found. Other resonances are obtained: Ξ*K¯* with IJP=0(12)− and 0(32)−. These pentaquark states is expected to be further verified in future experiments.
In this work, we study the masses and the two-body strong decay of the ρ and ρ3 states below 2 GeV in the framework of the chiral quark model and the P03 models. In the calculations, the wave functions of the partic...
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In this work, we study the masses and the two-body strong decay of the ρ and ρ3 states below 2 GeV in the framework of the chiral quark model and the P03 models. In the calculations, the wave functions of the particles are obtained numerically by the Gaussian expansion method, and they are applied in the decay calculation. By comparing the results with experimental data, we are trying to identify the exotic states. And it will be helpful to study the structures of ρ/ρ3 states.
A dynamical calculation of pentaquark systems with quark contents uudds¯ is performed in the framework of a quark delocalization color screening model with the help of the resonating group method. The effective p...
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A dynamical calculation of pentaquark systems with quark contents uudds¯ is performed in the framework of a quark delocalization color screening model with the help of the resonating group method. The effective potentials between baryon and meson clusters are given, and the possible bound states or resonances are investigated. The single calculations show that the NK* with I=0,JP=12−,ΔK* with I=1,JP=12−, and ΔK* with I=2,JP=32− are all bound, but they all turn into scattering states by coupling with the corresponding open channels. A possible resonance state ΔK* with I=1,JP=52− is proposed. The mass is around 2110.5 MeV, and the decay modes are NK in D wave and NKππ in P waves.
A dynamical calculation of pentaquark systems with quark contents uudds¯ is performed in the framework of quark delocalization color screening model with the help of resonating group method. The effective potenti...
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作者：
Yang, GangPing, JialunDepartment of Physics
Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China
Recently, the experimental results of LHCb Collaboration suggested the existence of five new excited states of Ω0c, Ωc(3000)0, Ωc(3050)0, Ωc(3066)0, Ωc(3090)0 and Ωc(3119)0, the quantum numbers of these new part...
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