Muon $(g-2)$ and Flavor Puzzles in the $U(1)^{}_{X}$-gauged Leptoquark Model

Abstract: We present an economical model where an $S^{}_1$ leptoquark and an anomaly-free $U(1)^{}_X$ gauge symmetry with $X = B^{}3-2L^{}\mu/3-L^{}_\tau/3$ are introduced, to account for the muon anomalous magnetic moment $a^{}_\mu \equiv (g^{}_\mu-2)$ and flavor puzzles including $R^{}{K^{(\ast){}}}$ and $R^{}{D^{(\ast){}}}$ anomalies together with quark and lepton flavor mixing. The $Z^\prime_{}$ gauge boson associated with the $U(1)^{}_X$ symmetry is responsible for the $R^{}{K^{(\ast){}}}$ anomaly. Meanwhile, the specific flavor mixing patterns of quarks and leptons can be generated after the spontaneous breakdown of the $U(1)^{}_X$ gauge symmetry via the Froggatt-Nielsen mechanism. The $S^{}_1$ leptoquark which is also charged under the $U(1)^{}_X$ gauge symmetry can simultaneously explain the latest muon $(g-2)$ result and the $R^{}{D^{(\ast){}}}$ anomaly. In addition, we also discuss several other experimental constraints on our model.