Flavour changing $Z'$ signals in a 6D inspired model

TL;DR

This paper explores the phenomenology of new neutral gauge bosons with flavor-changing couplings in a 6D model, linking their masses and interactions to potential signals in rare meson decays and collider experiments.

Contribution

It introduces a relation between gauge boson masses and couplings in a 6D model and uses an effective approach to connect rare meson decays with collider signals.

Findings

Heavy bosons are currently unreachable at LHC.

A systematic effective model relates meson decays to LHC observations.

Constraints can be relaxed in alternative model realizations.

Abstract

We consider the phenomenology of new neutral gauge bosons with flavour non-diagonal couplings to fermions, inherent in 6D models explaining successfully the hierarchy of masses as well as the mixing for quarks, charged leptons and neutrinos (this model can in particular be credited with the correct prediction of the neutrino mixing angle $\theta_{13}$). We present a general relation between masses of new gauge bosons and their couplings to fermions. We show that in the current realization of the model, the new heavy bosons are unreachable at LHC but argue why the constraint could be relaxed in the context of a different realization. In view of a more systematic study, we use an effective model inspired by the above to relate directly rare meson decays to possible LHC observations. In terms of effective Lagrangians, this can be seen as the introduction in the model of only one overall scaling parameter to extend our approach without modifying the 4D (gauge) structure.