Searching for flavored gauge bosons

Standard Model may allow an extended gauge sector with anomaly-free flavored gauge symmetries, such as L_i −L_j , B_i −L_j , and B −3L_i, where i, j = 1, 2, 3 are flavor indices. We investigate phenomenological implications of the new flavored gauge boson Z^′ in the above three classes of gauge symmetries. Focusing on the gauge boson mass above 5 GeV, we use the lepton universality test in the Z and τ /μ decays, LEP searches, LHC searches, neutrino trident production bound, and LHC Z → 4μ searches to put constraints on the g^′ −M_Z′ plane. When L₁ is involved, the LEP bounds on the e⁻e⁺ → ℓ⁻ℓ⁺ processes give the most stringent bounds, while the LHC bound becomes the strongest constraints in the large $M_{Z^{\prime }}$ region when B_i is involved. The bound from Z → 4μ productions, which is applicable for L₂-involved scenarios, provides stringent bounds in the small $M_{Z^{\prime }}$ region. One exception is the B − 3L₂ scenario, in which case only a small region is favored due to the lepton universality.