Test of lepton universality in beauty-quark decays
Test of lepton universality in beauty-quark decays
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DOI：
10.1038/s41567-021-01478-8
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发表时间：
2021-03
期刊：
影响因子：
19.6
通讯作者：
L. C. R. Aaij;C. Beteta;T. Ackernley;B. Adeva;M. Adinolfi;H. Afsharnia;C. Aidala;S. Aiola
中科院分区：
文献类型：
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作者：
L. C. R. Aaij;C. Beteta;T. Ackernley;B. Adeva;M. Adinolfi;H. Afsharnia;C. Aidala;S. Aiola
粒子物理学的标准模型目前为我们提供了基本粒子及其相互作用的最佳描述。该理论预言，不同的带电轻子，如电子、μ子和τ子，具有相同的电弱相互作用强度。先前的测量表明，大范围的粒子衰变都符合轻子普适性原理。本文基于欧洲核子研究中心大型强子对撞机LHCb探测器收集的质子-质子碰撞数据，提出了美夸克衰变中轻子普适性被打破的证据，其显著性为3.1标准差。测量的过程中，一个美丽的介子转化为一个奇怪的介子发射电子和正电子，或一个μ子和反μ子。如果被未来的测量所证实，这种违反轻子普适性的行为将意味着超越标准模型的物理学，例如夸克和轻子之间新的基本相互作用。
The standard model of particle physics currently provides our best description of fundamental particles and their interactions. The theory predicts that the different charged leptons, the electron, muon and tau, have identical electroweak interaction strengths. Previous measurements have shown that a wide range of particle decays are consistent with this principle of lepton universality. This article presents evidence for the breaking of lepton universality in beauty-quark decays, with a significance of 3.1 standard deviations, based on proton–proton collision data collected with the LHCb detector at CERN’s Large Hadron Collider. The measurements are of processes in which a beauty meson transforms into a strange meson with the emission of either an electron and a positron, or a muon and an antimuon. If confirmed by future measurements, this violation of lepton universality would imply physics beyond the standard model, such as a new fundamental interaction between quarks and leptons.