标题： 附加费米子和规范玻色子对$Re(ε'/epsilon)$的影响 显示英文标题

标题： Influence of Additional Fermions and Gauge Bosons on $Re(ε'/epsilon)$

摘要： CP破坏参数$Re(\epsilon'/\epsilon)$之前已在标准模型中计算过，结果以一种令人兴奋的方式依赖于顶夸克质量。 我们考虑结果在标准模型的两个具体扩展中如何改变。 第一个仅添加费米子，一个额外的矢量样夸克双态，并倾向于减少$Re(\epsilon'/\epsilon)$。 第二个包含三个扩展族，第三族被不同处理，并有额外的规范玻色子 - 331模型 - 并可以在给定$m_t$的情况下容纳更大的$Re(\epsilon'/\epsilon)$值。 当实验值$m_t$和$Re(\epsilon'/ \epsilon)$更准确时，将允许区分理论。 如果较低的实验数值$Re(\epsilon'/\epsilon) = (0.74 \pm 0.60) \times 10^{-3}$ (费米实验室，E731) 得到确认，且$m_t$接近 175GeV，那么标准模型是可接受的。 但是，如果较高的数值$Re(\epsilon'/\epsilon) = (2.3 \pm 0.65) \times 10^{-3}$ (欧洲核子研究中心，NA31) 仍然存在，一种类似于 331 模型的动力学似乎更受青睐，该模型中第三代与前两代不同处理，并且存在额外的规范玻色子。 显示英文摘要

摘要： The CP violation parameter $Re(\epsilon'/\epsilon)$ has previously been calculated in the standard model and the result depends on the top quark mass in an exciting way. We consider how the result is modified in two specific extensions of the standard model. The first adds only fermions, an extra vector-like quark doublet, and tends to reduce $Re(\epsilon'/\epsilon)$. The second contains three extended families with the third family treated differently and additional gauge bosons - the 331 model - and can accommodate larger values of $Re(\epsilon'/\epsilon)$ for a given $m_t$. When the experimental values of $m_t$ and $Re(\epsilon'/ \epsilon)$ are known more accurately, it will allow discrimination between theories. If the lower experimental number $Re(\epsilon'/\epsilon) = (0.74 \pm 0.60) \times 10^{-3}$ (Fermilab, E731) is confirmed and $m_t$ is near the value 175GeV the standard model is acceptable. But, if the higher value $Re(\epsilon'/\epsilon) = (2.3 \pm 0.65) \times 10^{-3}$ (CERN, NA31) persists, a dynamics like the 331 model where the third family is treated differently from the first two and there exist additional gauge bosons seems to be favored.