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1.
In the framework of the one-boson-exchange model, we have performed an extensive study of the possible B*B,B*B*,D*,D** molecular states with various quantum numbers after considering the S-wave and D-wave mixing. We also discuss the possible experimental research of these interesting states.  相似文献   

2.
In the framework of the one-boson-exchange model, we have performed an extensive study of the possible B*B, B*B*, D*D, D*D* molecular states with various quantum numbers after considering the S-wave and D-wave mixing. We also discuss the possible experimental research of these interesting states.  相似文献   

3.
刘翔 《中国物理 C》2010,34(9):1405-1407
In my talk,we present the dynamical study of Y(4140) and Y(3930) under the D*s D*s and D* D* molecular assignments respectively.The importance to theoretically and experimentally study their open-charm decay,hidden-charm decay,radiative decay and double-photon decay is proposed combing with the theoretical calculation of the decay behavior of Y(4140) and Y(3930).According to the recent new experimental progress made by Belle,we further indicate the reasonability of molecular explanation to Y(4140).Another event cluster around 4270 MeV in the J/ψφ invariant mass spectrum of B → KJ/ψφ can provide us more hints to reveal the creation mechanism of molecular structure in B meson decay,which will be helpful to clarify the underlying structure of Y(4140) and Y(3930).  相似文献   

4.
The light-induced frequency shift(LIFS)of ultracold molecular ro-vibrational levels originates from the strong coupling of the atomic-scattering state and the bound-molecular state.In this paper,we present our experimental determination of the LIFSs of the lowest vibrational levels(v=0,1)in the purely long-range 0^-g state of ultracold cesium molecules.A high-resolution double photoassociation spectroscopy is developed,which serves as frequency ruler to measure the frequency shifts of the lowest molecular levels for Cs2.The experimental results are qualitatively consistent with the theoretical expectations.  相似文献   

5.
Hadron molecules     
We discuss a possible interpretation of the open charm mesons D*s0 (2317),D s1 (2460) and the hidden charm mesons X(3872),Y(3940) and Y(4140) as hadron molecules.Using a phenomenological Lagrangian approach we review the strong and radiative decays of the D* s0 (2317) and D s1 (2460) states.The X(3872) is assumed to consist dominantly of molecular hadronic components with an additional small admixture of a charmonium configuration.Determing the radiative (γJ/ψ and γψ(2s)) and strong (J/ψ2π and J/ψ3π) decay modes we show that the present experimental observation is consistent with the molecular structure assumption of the X(3872).Finally,we give evidence for molecular interpretations of the Y(3940) and Y(4140) related to the observed strong decay modes J/ψ+ω or J/ψ+φ,respectively.  相似文献   

6.
The DK interaction is relevant to the interpretation of the DsJ(2317). We dynamically investigate S-wave DK interactions in the chiral SU(3) quark model by solving the resonating group method equation. The numerical results show an attraction between D and K, which is from boson exchanges between light quarks. However, such an attraction is not strong enough to form a DK molecule. Meanwhile, S partial wave phase shifts of DK elastic scattering are obtained. The case of S-wave D^*K is rather similar to that of DK. To draw a definite conclusion of whether a molecular state exists in DK or the D^*K system, more details of dynamics should be considered in a future study.  相似文献   

7.
Recently, there was a hot controversy about the concept of localized orbitals, which was triggered by Grushow's work titled "Is it time to retire the hybrid atomic orbital?" [J. Chem. Educ. 88, 860 (2011)]. To clarify the issue, we assess the delocalized and localized molecular orbitals from an experimental view using electron momentum spectroscopy. The delocalized and localized molecular orbitals based on various theoretical models for CH4, NH3, and H20 are compared with the experimental momentum distributions. Our results show that the delocalized molecular orbitals rather than the localized ones can give a direct interpretation of the experimental (e, 2e) results.  相似文献   

8.
In this paper, we present a simple theoretical approach to calculate the multiple ionization of big atoms and molecules induced by very high-q fast projectiles in a strong coupling regime (q/v 〉 1). The results obtained from this approach are in excellent agreement with the available experimental data. A probable scenario of molecular multiple ionization by fast and very high-q projectiles is discussed. The very small computational time required here and the good agreement with the existing experimental data make it a good candidate for studying the multiple ionization of complex molecules under high linear energy transfers.  相似文献   

9.
In this article, we take the vector charmonium-like state Y(4660) as a φ' fo(980) bound state (irrespective of the hadro-charmonium and the molecular state) tentatively, and study its mass using the QCD sum rules. The numerical value My = 4.71 ±0.26 GeV is consistent with the experimental data. Considering the SU(3) symmetry of the light flavor quarks and the heavy quark symmetry, we also study the bound states φ'a(400-1200), γ′″ fo(980), and γ′″σ(400-1200) with the QCD sum rules, and make reasonable predictions for their masses.  相似文献   

10.
In this study, we evaluate the values of lattice thermal conductivity κL of type Ⅱ Ge clathrate (Ge34) and diamond phase Ge crystal (d-Ce) with the equilibrium molecular dynamics (EMD) method and the Slack's equation. The key parameters of the Slack's equation are derived from the thermodynamic properties obtained from the lattice dynamics (LD) calculations. The empirical Tersoff's potential is used in both EMD and LD simulations. The thermal conductivities of d-Ge calculated by both methods are in accordance with the experimental values. The predictions of the Slack's equation are consistent with the EMD results above 250 K for both Ge34 and d-Ge. In a temperature range of 200-1000 K, the κL value of d-Ge is about several times larger than that of Ge34.  相似文献   

11.
A detailed theoretical analysis of determining the sum of flexoelectric coefficients in nematic liquid crystals using the capacitance method is given. In the strong anchoring parallel aligned nematic (PAN) and hybrid aligned nematic (HAN) cells, the dependences of the capacitance on the sum of flexoelectric coefficients and the applied voltage are obtained by numerical simulations, and the distributions of the director and the electric potential for different applied voltages and flexoelectric coefficients are also given. Based on this theoretical analysis, we propose an experimental design for measuring the capacitance of a liquid crystal cell using the improved precision LCR meter E4980A (Agilent). Through comparing the experimental data with the simulated results, the sum of flexoeletric coefficients can be determined.  相似文献   

12.
The condensation of DNA induced by spermine is studied by atomic force microscopy (AFM) and molecular dynamics (MD) simulation in this paper. In our experiments, an equivalent amount of multivalent cations is added to the DNA solutions in different numbers of steps, and we find that the process of DNA condensation strongly depends on the speed of adding cations. That is, the slower the spermine cations are added, the slower the DNA aggregates. The MD and steered molecular dynamics (SMD) simulation results agree well with the experimental results, and the simulation data also show that the more steps of adding multivalent cations there are, the more compact the condensed DNA structure will be. This investigation can help us to control DNA condensation and understand the complicated structures of DNA--cation complexes.  相似文献   

13.
We investigate the single-electron loss processes of light charged ions (Li^1+,2+, C^2+,3+,5+, and O^2+,3+) in collisions with helium. To better understand the experimental results, we propose a theoretical model to calculate the cross section of projectile electron loss. In this model, an ionization radius of the incident ion was defined under the classical over-barrier model, and we developed "strings" to explain the processes of projectile electron loss, which is similar with the molecular over-barrier model. Theoretical calculations are in good agreement with the experimental results for the cross section of single-electron loss and the ratio of double-to-single ionization of helium associated with one-electron loss.  相似文献   

14.
We construct a phenomenologica/KN interaction which reproduces the two resonances: the energy of the first resonance is 1420MeV and the other is 1392MeV. The A(1405) is found by a superposition of the two reso- nances with appropriate weights. Within the framework of the Brueckner-Hartree-Fock theory, we have studied K- - 3He(T = 0) and K- - 4He(T = 1/2). The binding energy BK- is 93MeV(72MeV) and the width F is 13 MeV(25 MeV) for K- - 3He(T =0) ( K- - 4He(T = 1/2)).  相似文献   

15.
The recently observed X(3872) resonance, which is difficult to assign a conventional cc charmonium state in the quark model, may be interpreted as a molecular state. Such a molecular state is a hidden flavor four quark state because of its charmonium-like quantum numbers. The s-channel one gluon exchange is an interaction which only acts in the hidden flavor multi-quark system. In this paper, we will study the X(3872) and other similiar hidden flavor molecular states in a quark model by taking into account the s-channel one gluon exchange interaction.  相似文献   

16.
Since the data show that Bell inequalities are violated experimentally, we must conclude that any hidden variable theory (which correctly predicts experimental data ) will be non-local. But, to conclude that the experimental violations of Bell inequalities show quantum mechanics to be non-local is unjustified. Specifically, the key assumptions required to obtain a Bell inequality are ( 1 ) locality and (2) the assignment of meaningful ( non- negative) probabilities to seemingly physical correlations (Bell expresses these correlations via " hidden variables" ). Since the Bell inequality is violated by experiment, at least one of these assumptions is wrong. The widespread conclusion that locality must be relinquished is valid only if we retain the previously mentioned correlations ( "hidden variables" ). We will demonstrate that the latter are not physical observables - they are not elements of physical reality.  相似文献   

17.
18.
陈元正  周密  孙美娇  里佐威  孙成林 《中国物理 B》2014,23(2):23302-023302
The pressure-induced molecular dissociation as one of the fundamental problems in physical sciences has aroused many theoretical and experimental studies. Here, using a newly developed particle swarm optimization algorithm, we investigate the high-pressure-induced molecular dissociation. The results show that the carbon tetrachloride (CC14) is unstable and dissociates into C2C16 and C12 under approximately 120 GPa and more. The dissociation is confirmed by the lattice dynamic calculations and electronic structure of the Pa3 structure with pressure evolution. The dissociation pressure is far larger than that in the case of high temperature, indicating that the temperature effectively reduces the activation barrier of the dissociation reaction of CC14. This research improves the understanding of the dissociation reactions of CC14 and other halogen compounds under high pressures.  相似文献   

19.
Density functional theory (DFT) with local density approximation (LDA) is employed to study the structural and electronic properties of the high explosive octahydro- 1,3,5, 7-tetranitro-1,3, 5, 7-tetrazocine (HMX) under high pressure compression up to 40 GPa. Pressure dependences of the cell volume, lattice constants, and molecular geometry of solid β-HMX are presented and discussed. It is found that N-N and N-C bonds are subject to significant change. This may implies that these bonds may be related to the sensitivity. The band gap is calculated and plotted as a function of pressure. Compared the experimental results with other theoretical works we find that LDA gives good results.  相似文献   

20.
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