Constraints on $Z^{\prime }$ Boson within Minimal Flavor Violation

Abstract

We explore a $Z^{\prime }$ boson coupled only with the Standard Model (SM) fermions ($Z^{\prime }f\bar{f}$) in the framework of Minimal Flavor Violation. We study its effects on the processes with lepton flavor violation ${\ell }_j\to {\ell }_i{\ell }_k{\bar{\ell }}_l$, ${\ell }_j\to {\ell }_i\gamma$, ${\mu }^{-}N\to e^{-}N$, quark flavor changing neutral currents $b\to s{\ell }^{+}{\ell }^{-}$, neutral $B$ and $K$ meson mixing, and $e^{+}{e}^{-}\to f\bar{f}$ at the LEP experiment to constrain the parameter space of $Z^{\prime }$ mass and couplings. We find that among those relevant processes, $\mu \to e\gamma$, $\mu \to 3e$, $\mu$-$e$ conversion and $e^{+}{e}^{-}\to f\bar{f}$ can put more stringent bounds on $Z^{\prime }f\bar{f}$ couplings normalized by $Z^{\prime }$ mass. Its implications on various processes are obtained, such as $B$ and $K$ mixing and $B/K\to M{\ell }_1{\bar{\ell }}_2$ decays. In addition, we also make analysis on $Z^{\prime }$ signatures at the LHC with $\sqrt{s}=8$ and 13 TeV.

Comments: 30 pages, 2 tables, 5 figures. v2: references and minor corrections for Fig.4 included