Speaker
Description
In order to simultaneously account for both $R_{D^{(\ast)}}$ and
$R_{K^{(\ast)}}$ anomalies in $B$-decays, we consider an extension
of the Standard Model by a single vector leptoquark field, and study
how one can achieve the required lepton flavour non-universality,
starting from a priori universal gauge couplings. While the unitary
quark-lepton mixing induced by $SU(2)_L$ breaking is insufficient,
we find that effectively nonunitary mixings hold the key to
simultaneously address the $R_{K^{(\ast)}}$ and $R_{D^{(\ast)}}$
anomalies. As an intermediate step towards various UV-complete
models, we show that the mixings of charged leptons with additional
vector-like heavy leptons successfully provide a nonunitary
framework to explain $R_{K^{(\ast)}}$ and $R_{D^{(\ast)}}$.
These realisations have a strong impact for electroweak
precision observables and for flavour violating ones: isosinglet
heavy lepton realisations are already excluded due to excessive
contributions to lepton flavour violating $Z$-decays.
Furthermore, in the near future, the expected progress in the sensitivity
of charged lepton flavour violation experiments should allow to fully probe
this class of vector leptoquark models.
| Secondary track (number) | 05. |
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