Pseudo-Axions in Little Higgs Models

In Little Higgs models, the Higgs mass is stabilized at the one-loop level by the mechanism of collective symmetry breaking. Typically, the basic ingredient of these models is a large(r) global symmetry group spontaneously broken at a scale of several TeV. The (light) Higgs appears as a Goldstone boson corresponding to a non-diagonal broken generator of this global symmetry. There could also be physical pseudoscalar particles present which belong to diagonal generators, having the properties of axions with masses in the range from several GeV up to the electroweak scale. We investigate the interesting phenomenology of these pseudo-axions at the linear collider as well as the photon collider.