论文标题
$ p $和$ cp $ symmetries的测试与$ e^+e^ - \ to j/ψ\至λ\barλ$
Testing of $P$ and $CP$ Symmetries with $e^+e^- \to J/ψ\to Λ\bar Λ$
论文作者
论文摘要
我们建议使用该过程$ e^+e^ - \ to j/ψ\至λ\barλ$测试$ p $ - 和$ cp $ -symetries。得出了该过程的角度分布的一般形式，并引入了拟议测试的几种可观察物。通过这些可观察到的物品，人们可以将$ p $抗合作物在$ j/ψ$生产中的效果从其衰减中分为一对$λ\barλ$。给出了由于SM中$ z $交换而导致的$ p $抗事的拟议不对称的数值估计。我们的结果表明，Besiii已经达到了探测这些影响的敏感性。在拟议的超级陶器工厂，其发光度增强了，它将能够以高精度测试SM预测。 $ cp $违反$ j/ψ\toλ\barλ$也可以进行测试。特别是，由于当前电动偶极矩的上限为$λ$，BESIII数据已经达到了违反$ cp $ cp $ cp $的敏感性。在拟议的超级陶器工厂，可以通过数量级来改善上限。
We propose to test $P$- and $CP$-symmetries with the process $e^+e^- \to J/ψ\to Λ\bar Λ$. The general form of the angular distribution of the process is derived and several observables for the proposed test are introduced. With these observables one can distinguish the effects of $P$-violations in the production of $J/ψ$ from its decay into a pair of $Λ\bar Λ$. Numerical estimations for proposed asymmetries of $P$-violation due to $Z$ exchange in SM are given. Our results show that BESIII has reached the sensitivity to probe these effects. At the proposed super-tau-charm factory with much enhanced luminosity it will be able to test the SM predictions with high precision. $CP$ violating effect in $J/ψ\to Λ\bar Λ$ can also be tested. In particular, BESIII data already reached the sensitivity to prove $CP$ violating effect due to current upper limit of electric dipole moment of $Λ$. At the proposed super-tau-charm factory the upper limit can be improved by an order of magnitude.
