Antisymmetric rank-2 tensor unparticle physics

We present the phenomenology of antisymmetric rank-2 tensor unparticle operator O_U,A^μν with scaling dimension d_U. We consider the physical effects of operator O_U,A^μν in Z⁰ boson invisible decays Z⁰→U, Z⁰→bb̅ channel, the electroweak precision observable S parameter, and the muon anomalous magnetic dipole moment. The Z⁰ boson invisible decay gives a very stringent constraint in the (Λ_U,M_U) plane, and only small r≡Λ_U/M_U≲0.1 is favored, when Λ_U is order of several 100 GeV. When the phenomenological parameter μ, which parameterizes the scale invariance breaking, goes to 0, the S parameter and the muon (g-2) diverge for 1<d_U<2, while for nonzero μ, there will be constraints on (Λ_U,M_U) which are more stringent than those obtained from collider experiments.