论文标题
在$ z $ -boson衰减中，搜索带有的带电的lepton-favour违规
Search for charged-lepton-flavour violation in $Z$-boson decays with the ATLAS detector
论文作者
论文摘要
除质量外，具有基本相同特性的瘦素分为三个家庭（或口味）。每种口味的瘦素数量在相互作用中保存下来，但这不是由基本原理施加的。由于粒子物理学的标准模型的表述，中微子中的风味振荡的观察表明，在中微子弱相互作用中，Lepton的风味并不保守。到目前为止，还没有实验证据表明这也发生在带电瘦素之间的相互作用中。这样的观察结果将是未被发现的粒子或尚未知道的相互作用的迹象。在这里，在CERN的大型强子对撞机上的Atlas实验报告说，在弱相互作用中对Lepton-Flavour侵入效果的限制，寻找$ Z $ -Boson衰减成$τ$ Lepton和另一个带有相反电荷的不同风味的Lepton。这些衰减的分支分数衡量的分支小于$ 8.1 \ times10^{ - 6} $（$eτ$）和$ 9.5 \ times10^{ - 6} $（$μτ$），使用139 fb $^{-1} $ of Proton-Proton collision $ sqr的置信度在95％的置信度下，以$^{-1} $ 20.3 fb $^{ - 1} $ at $ \ sqrt {s} = 8 $ tev。这些结果取代了二十多年前进行的大型电子峰撞机实验的限制。
Leptons with essentially the same properties apart from their mass are grouped into three families (or flavours). The number of leptons of each flavour is conserved in interactions, but this is not imposed by fundamental principles. Since the formulation of the standard model of particle physics, the observation of flavour oscillations among neutrinos has shown that lepton flavour is not conserved in neutrino weak interactions. So far, there has been no experimental evidence that this also occurs in interactions between charged leptons. Such an observation would be a sign for undiscovered particles or a yet unknown type of interaction. Here, the ATLAS experiment at the Large Hadron Collider at CERN reports a constraint on lepton-flavour-violating effects in weak interactions, searching for $Z$-boson decays into a $τ$ lepton and another lepton of different flavour with opposite electric charge. The branching fractions for these decays are measured to be less than $8.1\times10^{-6}$ ($eτ$) and $9.5\times10^{-6}$ ($μτ$) at 95% confidence level using 139 fb$^{-1}$ of proton-proton collision data at a centre-of-mass energy $\sqrt{s}=13$ TeV and 20.3 fb$^{-1}$ at $\sqrt{s}=8$ TeV. These results supersede the limits from the Large Electron-Positron Collider experiments conducted more than two decades ago.
