Almost-commutative geometries beyond the standard model II: new colours

We will present an extension of the standard model of particle physics in its almost-commutative formulation. This extension is guided by the minimal approach to almost-commutative geometries employed by Iochum et al (2004 J. Math. Phys. 45 5003 (Preprint hep-th/ 0312276)), Jureit and Stephan (2005 J. Math. Phys. 46 043512 (Preprint hep-th/ 0501134)), Schucker (2005 Preprint hep-th/0501181), Jureit et al (2005 J. Math. Phys. 46 072303 (Preprint hep-th/ 0503190)) and Jureit and Stephan (2006 Preprint hep-th/ 0610040), although the model presented here is not minimal itself. The corresponding almost-commutative geometry leads to a Yang-Mills-Higgs model which consists of the standard model and two new fermions of opposite electromagnetic charge which may possess a new colour-like gauge group. As a new phenomenon, grand unification is no longer required by the spectral action.