Sigma model on a squashed sphere with a Wess-Zumino term

Abstract

A class of two-dimensional sigma models interpolating between $C{P}^1$ and the $SU(2)$ principal chiral model is discussed. We add the Wess-Zumino-Novikov-Witten term and examine the renormalization group flow of the two coupling constants which characterize the model under consideration. The model flows to the $SU(2)$ WZNW conformal field theory in the IR. There is an ordinary phase in which the model flows from the asymptotically free $C{P}^1$ model coupled to an extra massless degree of freedom in the UV. At higher loop order we discover that there is also a phase in which the model can flow from non-trivial fixed points in the UV. A non-perturbative confirmation of these extra fixed points would be desirable.

v4. Updated acknowledgements

References in corpus (4)

• On deformations of AdS_n x S^n supercosets
• Yangian symmetry in deformed WZNW models on squashed spheres
• Hidden Yangian symmetry in sigma model on squashed sphere
• Integrable sigma models and 2-loop RG flow

Cited by in corpus (3)

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• Integrability vs. RG flow in $G\times G$ and $G\times G/H$ sigma models
• Improvement of a conserved current density versus adding a total derivative to a Lagrangian density