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Title: Test of lepton universality in beauty-quark decays
Abstract 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.
Authors:
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Award ID(s):
2102879
Publication Date:
NSF-PAR ID:
10349065
Journal Name:
Nature Physics
Volume:
18
Issue:
3
Page Range or eLocation-ID:
277 to 282
ISSN:
1745-2473
Sponsoring Org:
National Science Foundation
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