Weak dipole moments of heavy fermions with flavor violation induced by $Z^\prime$ gauge bosons

TL;DR

This paper calculates weak dipole moments of heavy fermions within a model with flavor-changing $Z'$ gauge bosons, providing numerical predictions for the $ au$ lepton and top quark that could inform future experimental searches.

Contribution

It presents the first detailed numerical analysis of weak dipole moments of heavy fermions induced by flavor-violating $Z'$ interactions at one-loop level.

Findings

Real part of $a^w_{\tau}$ is around $10^{-9}$

Real part of $a^w_t$ is around $10^{-7}$

WEDM $d^w_{\tau}$ up to $10^{-26}$ e-cm

Abstract

A calculation of weak dipole moments of charged fermions of the Standard Model (SM) at the one-loop level, in the context of a general effective extended neutral current model with flavor changing $Z^\prime f_i \bar{f}_j$ vertices, is presented. We give numerical predictions for the anomalous weak magnetic dipole moment (AWMDM) $a^w_{fi}$, and the weak electric dipole moment (WEDM) $d^w_{f_i}$, for the $\tau$ lepton and $t$ quark. For several $Z^\prime$ gauge bosons considered, we find that, for the $\tau$ lepton, the best prediction for the real part of $a^w_{\tau}$ is of the order of $10^{-9}$, while the imaginary part is four orders of magnitude below. The highest value for the WEDM, $d^w_{\tau}$, corresponds to $10^{-26}$ $e$-cm, for its real part, and the imaginary part is three orders of magnitude below. On the other hand, we found for the top quark, that the best prediction for the real part of $a^w_t$ is of the order of $10^{-7}$ and its imaginary part is of the order of $10^{-11}$. We also found that $d^w_t$ is of the order of $10^{-26}$ $e$-cm for its real part, and its imaginary part can be as high as $10^{-31}$ $e$-cm.