Gauge coupling unification and light Exotica in String Theory

Understand

In this letter we consider the consequences for the LHC of light vector-like exotica with fractional electric charge.

• It is shown that such states are found in orbifold constructions of the heterotic string.
• Moreover, these exotica are consistent with gauge coupling unification at one loop, even though they do not come in complete multiplets of SU(5).