$\mu$ term and supersymmetry breaking from six dimensional theory

Abstract

We propose a new next-to-minimal supersymmetric standard model (NMSSM) which is on a six-dimensional spacetime compactified on a $T^2/Z_3$ orbifold. In this model, three gauge singlet fields $N, S_1$ and $S_2$ in addition to the minimal supersymmetric standard model (MSSM) fields are introduced. These fields are localized at some fixed points except for the singlet $N$ and the gauge fields. The $\mu$ parameter is provided from the vacuum expectation value (vev) of $N$. The $F$ terms get vevs simultaneously, and the gauginos mediate the supersymmetry breaking to the MSSM sector. Both of these parameters are strongly suppressed due to the profile of $N$. Thus these parameters induced from those of the order of the so-called GUT scale can become close to the electroweak scale without unnatural fine tuning.