Unitarity Bounds for Gauged Axionic Interactions and the Green-Schwarz Mechanism

Abstract

We analyze the effective actions of anomalous models in which a four-dimensional version of the Green-Schwarz mechanism is invoked for the cancellation of the anomalies, and we compare it with those models in which gauge invariance is restored by the presence of a Wess-Zumino term. Some issues concerning an apparent violation of unitarity of the mechanism, which requires Dolgov-Zakharov poles, are carefully examined, using a class of amplitudes studied in the past by Bouchiat-Iliopoulos-Meyer (BIM), and elaborating on previous studies. In the Wess-Zumino case we determine explicitly the unitarity bound using a realistic model of intersecting branes (the Madrid model) by studying the corresponding BIM amplitudes. This is shown to depend significantly on the Stückelberg mass and on the coupling of the extra anomalous gauge bosons and allows one to identify Standard-Model-like regions (which are anomaly-free) from regions where the growth of certain amplitudes is dominated by the anomaly, separated by an inflection point which could be studied at the LHC. The bound can even be around 5-10 TeV's for a $Z^{\prime }$ mass around 1 TeV and varies sensitively with the anomalous coupling. The results for the WZ case are quite general and apply to all the models in which an axion-like interaction is introduced as a generalization of the Peccei-Quinn mechanism, with a gauged axion.

50 pages, 28 figures

References in corpus (8)

• Evidence for a new light spin-zero boson from cosmological gamma-ray propagation?
• Anomalies, Anomalous U(1)'s and generalized Chern-Simons terms
• Axion-Like Particles, Cosmic Magnetic Fields and Gamma-Ray Astrophysics
• Stuckelberg Axions and the Effective Action of Anomalous Abelian Models 1. A unitarity analysis of the Higgs-axion mixing
• Windows over a New Low Energy Axion
• Stuckelberg Axions and the Effective Action of Anomalous Abelian Models 2. A SU(3)_C x SU(2)_W x U(1)_Y x U(1)_B model and its signature at the LHC
• Trilinear Anomalous Gauge Interactions from Intersecting Branes and the Neutral Currents Sector
• Axial anomaly: the modern status

Cited by in corpus (8)

• Searching for Extra Z' from Strings and Other Models at the LHC with Leptoproduction
• Trilinear Anomalous Gauge Interactions from Intersecting Branes and the Neutral Currents Sector
• Gravity and the Neutral Currents: Effective Interactions from the Trace Anomaly
• Effective Field Theory of Stückelberg Vector Bosons
• A Light Supersymmetric Axion in an Anomalous Abelian Extension of the Standard Model
• Axi-Higgs portal Dark Matter via Wess-Zumino mechanism
• Dark matter annihilation into gamma-ray line generated by anomalies
• Conformal anomaly actions for dilaton interactions