查询词典 kaon

neutral kaon system, effective Hamiltonian theory, state evolution matrix, CP and CPT violation parameter

一类仍采用有效哈密顿量描述体系，但有效哈密顿量不再只准到弱作用二阶，而是包括了高阶修正项。

The contributions ofΨp from the pion and the kaon meson, the contribution ofΨB from B meson are not very small, and can not be safely neglected for giving more resonable results of form factors.The B meson wavefunction is a major source of uncertainty in the study of B meson decays. The B→πand B→K transition form factors provide a good platform to determine the possible regions for the two typical phenomenological parametersΛandδ.

但π、K介子波函数中的Ψp和B介子波函数中的ΨB对形状因子的贡献比较大，为了获得更加合理的形状因子的结果，一般不能忽略π、K介子波函数中的Ψp和B介子波函数中的ΨB项的贡献。B介子波函数是B介子衰变中不确定性的一个主要的来源。B→π和B→K跃迁形状因子为确定两个典型的唯象参数Λ和δ提供了一个很好的平台。

In this paper we calculate the normalization constants mp_ 0π and mp_ 0K of the twist-3 distribution amplitudes of the pion and kaon from the QCD sum rules,instead of using the equations of motion.

用QCD求和规则计算了π介子和K介子的两个twist3分布振幅的归一化常数mp0π和mp0K。

In the "indirect" process, first observed in neutral kaon particles in 1964, quantum mechanics allows particles to change into their antiparticles and back again in a process known as "mixing". In 2001, The BaBar team, working at the Stanford Linear Accelerator -- and independently the Belle collaboration at the KEK laboratory in Japan -- were the first experiments to detect this in a B meson. BaBar observed "direct" CP violation in 2004 by showing that the number of decays observed for B mesons was higher than for their antiparticle equivalents.

在&间接&过程中，量子力学允许粒子在一种被称为&混合&的过程中，在自身与其反粒子之间相互转变。1964年人们第一次在中性K介子上观测到这种现象。2001年，在斯坦福直线加速器中心工作的BaBar研究组和另一个日本高能加速器研究中心的Belle研究小组各自独立地第一次在实验中观测到这种现象发生在B介子上。2004年，BaBar小组观测到了&直接&电荷宇称不守恒，他们发现观察到的B介子的衰变数量要高于其对应的反物质。

For de- scribing this system precisely,we use the state evolution matrix without using the Wigner- Weisskopf spproximation and get four complex parameters to describe the CP and CPT voila- tion properties of nuetral kaon system.

这一理论是由Lee，Oeheme和Yang在50年代提出的【'&」，其核心是采用了Wign。。－Wei.kopf近似'&，使得理论可以用一个有效哈密顿量近似地描述。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。