Some Issues in a Gauge Model of Unparticles

Abstract

We address in a recent gauge model of unparticles the issues that are important for consistency of a gauge theory, i.e., unitarity and Ward identity of physical amplitudes. We find that non-integrable singularities arise in physical quantities like cross section and decay rate from gauge interactions of unparticles. We also show that Ward identity is violated due to the lack of a dispersion relation for charged unparticles although the Ward-Takahashi identity for general Green functions is incorporated in the model. A previous observation that the unparticle's (with scaling dimension d) contribution to the gauge boson self-energy is a factor (2-d) of the particle's has been extended to the Green function of triple gauge bosons. This (2-d) rule may be generally true for any point Green functions of gauge bosons. This implies that the model would be trivial even as one that mimics certain dynamical effects on gauge bosons in which unparticles serve as an interpolating field.

v1:16 pages, 3 figures. v2: some clarifications made and presentation improved, calculation and conclusion not modified; refs added and updated. Version to appear in EPJC

References in corpus (18)

• Unparticle Physics
• Another Odd Thing About Unparticle Physics
• Collider signals in unparticle physics
• Bounds on Unparticles Couplings to Electrons: from Electron g-2 to Positronium Decays
• Some Phenomenologies of Unparticle Physics
• Long-range Electron Spin-spin Interactions from Unparticle Exchange
• Scalar modifications to gravity from unparticle effects may be testable
• Colored Unparticles
• Long range forces and limits on unparticle interactions
• Effects of Unparticles on Running of Gauge Couplings
• Unparticle Induced Baryon Number Violating Nucleon Decays
• Electromagnetic Dipole Moments and Radiative Decays of Particles from Exchange of Fermionic Unparticles
• Unparticle actions and gauge invariance
• Comments on "Gauge Fields and Unparticles"
• Gauge Fields and Unparticles
• The Mandelstam-Terning Line Integral in Unparticle Physics -- A Reply to Galloway, Martin and Stancato
• The Gauged Unparticle Action
• Wilson Line Integrals in the Unparticle Action

Cited by in corpus (1)

• Unparticle actions and gauge invariance