Global Analysis of Leptophilic Z' Bosons

Understand

New neutral heavy gauge bosons ($Z^\prime$) are predicted within many extensions of the Standard Model.

• While in case they couple to quarks the LHC bounds are very stringent, leptophilic $Z^\prime$ bosons (even with sizable couplings) can be much lighter and therefore lead to interesting quantum effects in precision observables (like $(g-2)_\mu$) and generate flavour violating decays of charged leptons.
• In particular, $\ell\to\ell^\prime\nu\bar\nu$ decays, anomalous magnetic moments of charged leptons, $\ell\to\ell^\prime\gamma$ and $\ell\to3\ell^\prime$ decays place stringent limits on leptophilic $Z^\prime$ bosons.
• Furthermore, in case of mixing $Z^\prime$ with the SM $Z$, $Z$ pole observables are affected.