Heavy-meson physics and flavour violation with a single generation

TL;DR

This paper investigates flavour-violating decays involving heavy mesons mediated by Kaluza-Klein gauge bosons in a model where three fermion generations originate from a single six-dimensional generation, setting bounds on extra dimension size.

Contribution

It introduces a model linking three fermion generations to a single six-dimensional origin and analyzes its implications for heavy meson decay processes and related bounds.

Findings

Bound on extra dimension size: 1/R > 3.3 TeV from B_s to K mu e decay.

Stronger bound from K to mu e decay: 1/R > 64 TeV.

Potential signature: observing K to mu e and B_s to K mu e decays without other flavour violations.

Abstract

We study flavour-violating processes which involve heavy B- and D-mesons and are mediated by Kaluza-Klein modes of gauge bosons in a previously suggested model where three generations of the Standard Model fermions originate from a single generation in six dimensions. We find the bound on the size R of the extra spatial dimensions 1/R>3.3 TeV, which arises from the three-body decay B_s to K mu e. Due to the still too low statistics this bound is much less stringent than the constraint arising from K to mu e, 1/R>64 TeV, which was found in a previous work (Frere et al., JHEP, 2003). Nevertheless, we argue that a clear signature of the model would be an observation of K to mu e and B_s to K mu e decays without observations of other flavour and lepton number changing processes at the same precision level.