$E_6$ Motivated UMSSM Confronts Experimental Data

Understand

We test $E_6$ realisations of a generic $U(1)'$ extended Minimal Supersymmetric Standard Model (UMSSM), parametrised in terms of the mixing angle pertaining to the new $U(1)'$ sector, $\theta_{E_6}$, against all currently available data, from space to ground experiments, from low to high energies.

• We find that experimental constraints are very restrictive and indicate that large gauge kinetic mixing and $\theta_{E_6}\approx -\pi/3$ are required within this theoretical construct to achieve compliance with current data.
• The consequences are twofold.
• On the one hand, large gauge kinetic mixing implies that the $Z'$ boson emerging from the breaking of the additional $U(1)'$ symmetry is rather wide since it decays mainly into $WW$ pairs.