Classification of standard-like heterotic-string vacua

We extend the free fermionic classification methodology to the class of standard-like heterotic-string vacua, in which the SO(10) GUT symmetry is broken at the string level to SU(3)×SU(2)×U(1)2. The space of GGSO free phase configurations in this case is vastly enlarged compared to the corresponding SO(6)×SO(4) and SU(5)×U(1) vacua. Extracting substantial numbers of phenomenologically viable models therefore requires a modification of the classification methods. This is achieved by identifying conditions on the GGSO projection coefficients, which are satisfied at the SO(10) level by random phase configurations, and that lead to three generation models with the SO(10) symmetry broken to the SU(3)×SU(2)×U(1)2 subgroup. Around each of these fertile SO(10) configurations, we perform a complete classification of standard-like models, by adding the SO(10) symmetry breaking basis vectors, and scanning all the associated GGSO phases. Following this methodology we are able to generate some 107 three generation Standard-like Models. We present the results of the classification and one exemplary model with distinct phenomenological properties, compared to previous SLM constructions.