查询词典 antiquark

The quark axial vector current operator includesnot only the Pauli spin operator, but also a relativistic reduction operator and a quark-antiquark pair creationoperator.

在质子静止坐标系，夸克轴矢量流除了Pauli自旋算符外，还有相对论修正项和海夸克对产生湮灭项。

In this thesis the process of constructing the non-perturbative Hamiltonian theory is de-scribed and is applied to estimate the vacuum condensate. It contains the following contents:At the very beginning, by using the path integral method and eliminating the gluon freedom, aGCM action 〓 of current quarks including lower order current-current coupling was derivedfrom the QCD Lagrangian and the effective Hamiltonian operator that could hardly be doneby the normal methods was derived. After doing this, the broken vacuum is introduced whichincludes quark-antiquark condensate through the generalized Bogoliubov-Valatin transformation,the effective Hamiltonian of constituent quark was derived. The detailed formulas containingthe spatial current-current coupling term for the effective Hamiltonian and gap equations wasworked out by parameterizing the correlation kernel as a quadratic potential. And then, the gapequation was solved and the quark-antiquark condensate of vacuum was studied both in the casesof instantaneous interaction and retarded interaction. In the end, the effective Hamiltionian withtwo-body quark-quark interaction was derived with one-body approximation, and with the helpof the functional integral method the coupling non-linear dynamic equations for systems withnuclear matter was derived. Finally, these equations were solved by selfconsistent method andthe effect of nuclear matter on vacuum condensate was studied. The spatial current-current coupling term is too difficult to handle, hence the correlationkernel is assumed to be not important and usually omitted in the pure vacuum condensate, andthe instantaneous interaction generally is adopted. Retaining the spatial current-current termand partial retardation effect, the quark pairs condensate in pure vacuum was studied, and theeffect of quark mass was also studied. At present, little study is focused in the case with nuclearmatter and spatial current-current term also omitted. Under the approximation with partialspatial current-current term, the effect of nuclear matter on vacuum condensate was studied.

本论文描述了量子色动力学整体色对称模型哈密顿量方法的构建过程，得到了反映正反夸克对凝聚真空结构的关于组分夸克的有效哈密顿量算符，它隐含了胶子作用，并且准确至流-流耦合项；接着，通过参数化哈密顿量中的夸克作用关联核，导出平方禁闭势参数化选择的哈密顿量的具体公式和能隙方程；随后，应用公式，编程求解，考察了瞬时作用下和部分延迟作用下真空的正反夸克对凝聚，在计算中保留了空间流-流耦合作用；之后，导出瞬时势和延迟势下包含二体作用项的哈密顿量公式，并采用单体化近似，通过泛函变分方法得到核物质存在时耦合的非线性动力学方程；在保留部分空间双流耦合作用的近似下，求解核物质的动力学方程，考察核物质密度对真空凝聚的影响，以往考察真空凝聚，对关联核的选用，由于空间流-流耦合项不易处理，也认为作用不大，常忽略该项，并且常采用瞬时作用；本文保留空间双流项和部分延迟作用，考察了真空情形的夸克对凝聚，还考察了夸克质量对纯真空凝聚的影响，以往对核物质存在情形的真空凝聚考察很少，也都忽略空间流-流项，本文在考虑部分空间流-流项近似下，考察了核物质存在对真空凝聚的影响。

While deriving the effective potential by calculating the elastic scattering amplitude between quark-antiquark,one would encounter the ordering problem.

由动量空间计算得到的夸克和反夸克之间的散射振幅推导坐标空间等效势时，总要出现算符排序问题，这是一个量子力学中长期存在而又未能得到很好解决的重要问题。

Meson: Any member of a family of subatomic particle s composed of a quark and an antiquark.

介子：由一个夸克和一个反夸克组成的亚原子粒子族。

Meson: Any member of a family of subatomic particles composed of a quark and an antiquark.

介子：由一个夸克和一个反夸克组成的亚原子粒子族。

Meson: Any member of a family of subatomic particles compose d of a quark and an antiquark.

介子：由一个夸克和一个反夸克组成的亚原子粒子族。

After a brief summary of the polarization of the initial quark or antiquark in these reactions,we give the calculation method of the polarization of hyperon.

在总结这些反应产生的初始夸克或反夸克极化的基础上，给出了超子极化的计算方法。

A B meson is a short-lived particle made up of both matter and antimatter -- one quark and one antiquark.

B介子是一种由物质和反物质组成的短寿命粒子。

For the system such as NN,π〓π〓 in which there are not quark and antiquark with the same flavor, only t-channel OGEP is needed to consider; but for the system such as K〓 in which a quark and an antiquark may have the same flavor, the effect of q〓 annihilation must be taken into account.

对于不含有相同味道夸克—反夸克的相互作用体系如NN，π〓π〓，显然是合理的；但对于类似πN，K〓这类含有相同味道夸克—反夸克的体系，湮灭道的贡献必须考虑。

Integrating out the small parts of the quark and antiquark fields but keeping both the quark and antiquark freedom in QCD, we get an effective Lagrangian which contains quark, antiquark and quark-antiquark mixing terms.

从QCD拉氏量出发，同时保留其中正，反夸克自由度贡献，仅将正，反夸克场中的小分量积分出去而得到一个包含正夸克项，反夸克项及正反夸克耦合项的拉氏量。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。