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1.
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   

2.
The prompt fission neutron spectra for the neutron-induced fission of 233U for low energy neutrons (below 6 MeV) are calculated using nuclear evaporation theory with a semi-empirical method, in which the partition of the total excitation energy between the fission fragments for the nth+233U fission reactions is determined by the available experimental and evaluation data. The calculated prompt fission neutron spectra agree well with the experimental data. The proportions of high-energy neutrons of prompt fission neutron spectrum versus incident neutron energies are investigated with the theoretical spectra, and the results are consistent with the systematics. The semi-empirical method could be a useful tool for the prompt evaluation of fission neutron spectra.  相似文献   

3.
刘翔 《中国物理 C》2009,33(12):1307-1311
In this talk, we firstly overview the experimental status of Nx(1625), which is an enhancement structure observed in K-3. invariant mass spectrum of J/ψ → pK-∧. process. Then we present the result of the decay of Nx(1625) under the two molecular assumptions, i.e. S-wave∧K- and S-wave ∑0K- molecular states. Several experimental suggestions for Nx (1625) are proposed.  相似文献   

4.
The QCD sum rule approach is used to analyze the nature of the recently observed new resonance X (4350), which is assumed to be a diquark-antidiquark state [cs][cs] with jPC = 1-+. The interpolating current representing this state is proposed. In the calculation, contributions of operators up to dimension six are included in the operator product expansion (OPE), as well as terms which are linear in the strange quark mass ms. We find ml-+ = (4.82 ~ 0.19) GeV, which is not compatible with the X(4350) structure as a 1-+ tetraquark state. Finally, we also discuss the difference of a four-quark state's mass whether the state's interpolating current has a definite charge conjugation.  相似文献   

5.
The structural and electronic properties of the 0.5 ML-terminated allyl mercaptan (ALM)/Si(IO0)-(2 x 1) surface are studied using the density functional method. The calculated absorption energy of the ALM molecule on the 0.5 ML-terminated ALM/Si(IO0)-(2 x 1) surface is 3.36eV, implying that adsorption is strongly favorable. The electronic structure calculations show that the ALM/Si(IO0)-(2 x 1), the clean Si(100)-(2 x 1), and the fully-terminated H/Si(IO0)-(2 ~ 1) surfaces have the nature of an indirect band gap semiconductor. The highest occupied molecular orbital is dominated by the ALM, confirming the mechanism proposed by Hossain for its chain reaction.  相似文献   

6.
Reanalysis of the photoassociation spectrum of the weakly binding (6S1/2 + 6P3/2) lg 133Cs2 levels, reported in the previous study [J. Mol. Spectro. 255 (2009) 106], is performed by using a Lu-Fano graph coupled to the improved LeRoy- Bernstein formula including two additional modified terms. A more accurate coefficient (c3) is obtained for the leading long-range potential (-c3/R3) of a diatomic molecule.  相似文献   

7.
A non-relativistic microscopic mean field theory of finite nuclei is investigated where the nucleus is described as a collection of nucleons and delta resonances. The ground state properties of 90Zr nucleus have beeninvestigated at equilibrium and large amplitude compression using arealistic effective baryon-baryon Hamiltonian based on Reid Soft Core (RSC)potential. The sensitivity of the ground state properties is studied, suchas binding energy, nuclear radius, radial density distribution, and singleparticle energies to the degree of compression. It is found that the mostof increasing in the nuclear energy generated under compression is used tocreate the massive δ particles. For 90Zr nucleus under compression at 2.5 times density of the normal nuclear density, the excited nucleons to δ's are increased sharply up to 14% of the total number of constituents. This result is consistent with the values extracted from relativistic heavy-ion collisions. The single particle energy levels are calculated and their behaviors under compression are examined too. A good agreement between results with effective Hamiltonian and thephenomenological shell model for the low lying single-particle spectra isobtained. A considerable reduction in compressibility for the nucleus, andsoftening of the equation of state with the inclusion of the $\Delta $'s inthe nuclear dynamics are suggested by the results.  相似文献   

8.
伍冬兰  谢安东  余晓光  万慧军 《中国物理 B》2012,21(4):43103-043103
The equilibrium structure of flue gas SO2 is optimized using the density functional theory (DFT)/B3P86 method and CC-PV5Z basis. The result shows that it has a bent (C2v, X1A1) ground state structure with an angle of 119.1184°. The vibronic frequencies and the force constants are also calculated. Based on the principles of atomic and molecular reaction statics (AMIIS), the possible electronic states and reasonable dissociation limits for the ground state of SO2 molecule are determined. The potential functions of SO and 02 are fitted by the modified Murrell-Sorbie+c6 (M-S+c6) potential function and the fitted parameters, the force constants and the spectroscopic constants are obtained, which are all close to the experimental values. The analytic potential energy function of the SO2 (X1A1) molecule is derived using the many-body expansion theory. The contour liues are constructed, which show the static properties of SO2 (XIA1), such as the equilibrium structure, the lowest energies, the most possible reaction channel, etc.  相似文献   

9.
The adsorption and reaction of CO on SrTiO3 (100) surface with and without surface oxygen vacancy are investigated by the first-principles calculation based on the density functional theory. The calculated results reveal that the oxygen vacancy site prefers to the activation of the C-O bond. The adsorption energies increase to 1.0855 and 0.3245eV for defect-CO and defect-OC orientations, respectively. Particularly the C-O bond is elongated by about 0.1285 ? in the defect-OC orientation compared with that in the Ti-OC one without surface oxygen vacancies. There is predominantly a chemisorption mechanism between the CO molecule and the surface in the defect-CO orientation.  相似文献   

10.
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   

11.
惠萍 《中国物理 C》2004,28(5):487-490
采用无规相近似(RPA)耦合集团展开方法,计算出2?+1维SU(2?)格点规范场的三到六阶真空波函数和真空能量.在计算中,用空心图构成试探波函数,得到的三到六阶真空波函数的计算结果在弱耦合区1g2〉1.2都表现出良好的标度行为.与较早的计算结果比较,采用RPA方法计算的真空波函数比采用非RPA方法计算的结果的标度行为有大幅度的改善.采用RPA方法计算的真空能量比采用非RPA方法计算的真空能量略低,这表明此方法是成功的方法.  相似文献   

12.
From Bethe–Salpeter equation, we deduce the equation which describes the two-body system consisting of a scalar meson and a vector meson. This equation is applied to investigate the exotic narrow state X(3872) assumed as a molecule state composed of D0D*0. The contribution of the resonance D-0 is the attractive interaction between two heavy mesons in this molecule state. The calculated mass of X is consistent with the experimental data.  相似文献   

13.
从格点U(1)规范场论中改进的哈密顿量出发,推导出截断本征方程.并对2+1维U(1)规范场真空波函数进行数值计算,验证了理论的预言:对格点哈密顿量进行改进能使真空波函数的标度行为明显地改善.  相似文献   

14.
2+1维格点QCD真空波函数的计算   总被引:1,自引:1,他引:0  
用改进的格点哈密顿量和截断本征方程法计算2+1维QCD真空波函数,结果显示出良好的标度行为.  相似文献   

15.
A new generalized F-expansion method is introduced and applied to the study of the (2+1)-dimensional Boussinesq equation. The further extension of the method is discussed at the end of this paper.  相似文献   

16.
惠萍 《中国物理 C》2000,24(6):490-494
改进了耦合集团展开方法,计算出的2+1维SU(2)格点规范场的真空波函数的μ0和μ2比用改进前的方法所得到的结果好,在弱耦合区表现出良好的标度行为  相似文献   

17.
惠萍 《中国物理 C》2005,29(4):345-349
采用无规相近似(RPA)耦合集团展开方法求解薛定谔本征值方程,计算高阶胶球波函数. 在计算中,用空心Wilson圈图作为试探波函数,对特殊Wilson圈图作近似处理,计算出的2+1维SU(2)格点规范场的六阶和七阶胶球波函数的μ0F和μ2F及相关参数z 在弱耦合区(β=4.8-9.6)出现较好的标度行为,七阶真空能量在整个区域(β=0.8-8.0)与六阶真空能量一致.  相似文献   

18.
In this paper,the (2+1)-dimensional generalization of shallow water wave equation,which may be used to describe the propagation of ocean waves,is analytically investigated.With the aid of symbolic computation,we prove that the (2+1)-dimensional generalization of shallow water wave equation possesses the Painlev property under a certain condition,and its Lax pair is constructed by applying the singular manifold method.Based on the obtained Lax representation,the Darboux transformation (DT) is constructed.The first iterated solution,second iterated solution and a special N-soliton solution with an arbitrary function are derived with the resulting DT.Relevant properties are graphically illustrated,which might be helpful to understanding the propagation processes for ocean waves in shallow water.  相似文献   

19.
2+1维U(1)格点规范场论中真空态的研究   总被引:2,自引:2,他引:0  
对2+1维U(1)格点规范场论真空态进行研究,仔细推导出连续极限下真空谈函数中参数μ0和μ2的普适表达式,并用截断本征方程法进行数值计算.  相似文献   

20.
If the recently discovered charmonium state X( 3872) is a loosely bound S-wave molecule of the charm mesons D0 D(*0) or D(*0) D0, it can be produced in B-meson decay by the coalescence of charm mesons. If this coalescence mechanism dominates, the ratio of the differential rate for B+ -->D(0) D(* 0)K+ near the D0 D(*0) threshold and the rate for B+ -->XK+ is a function of the D0 D(*0) invariant mass and hadron masses only. The identification of the X( 3872) as a D0 D(*0)/D(*0)D0 molecule can be confirmed by observing an enhancement in the D0 D(*0) invariant mass distribution near the threshold. An estimate of the branching fraction for B+ -->XK+ is consistent with observations if X has quantum numbers J(PC)=1(++ ) and if J/psi pi(+) pi(-) is one of its major decay modes.  相似文献   

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