New Flavor Interactions at the LHC

Abstract

For a new family-nonuniversal gauge interaction to be accessible at the LHC it will most likely couple preferentially to the third family. By coupling to all members of the third family the production of a new gauge boson (the $X$ with $M_X\approx1$ TeV) will lead to final states with a distinctive $\tau^+\tau^-$ pair. We study the mass reconstruction of the $X$ and the cuts that can enhance signal to background. The $X$ boson should be associated with the physics of flavor and in the simplest picture a fourth family. We discuss how the mass mixing between the third and fourth families affects the $X$ couplings and a possible mixing with the $Z$.