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Quark-Lepton Nonuniversality

Xiao-Yuan Li·Ernest Ma
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Abstract

There is new experimental evidence which may be interpreted as a small departure from quark-lepton universality. We propose to understand this as the result of a hierarchy of mass scales in analogy to $m_u, m_d << Λ_{QCD}$ for strong isospin. We show $(G_F)^{NC}_{lq} < (G_F)^{CC}_{lq} < (G_F)^{CC}_{ll} < (G_F)^{NC}_{ll}$ in principle, but all are still approximately equal. New physics is predicted at the TeV scale.

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Xiao-Yuan Li, Ernest Ma. 2003-01-02. Quark-Lepton Nonuniversality. https://arxiv.org/abs/hep-ph/0301006

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