Unparticle physics with broken scale invariance

Abstract: If scale invariance is exact, unparticles are unlikely to be probed in colliders since there are stringent constraints from astrophysics and cosmology. However these constraints are inapplicable if scale invariance is broken at a scale . The case is particularly interesting since it allows unparticles to be probed at and below the Z pole. We show that μ can naturally be in this range if only vector unparticles exist, and briefly remark on implications for Higgs phenomenology. We then obtain constraints on unparticle parameters from cross-section and forward–backward asymmetry data, and compare with the constraints from mono-photon production and the Z hadronic width. [Copyright &y& Elsevier]