Same sign top-pairs in a non-universal Z model at the LHC

We analyse same sign dilepton signatures in a non-universal flavor changing Z model. These arise due to tt (or t_bar t_bar) production processes due to the semi-leptonic decays of (anti)tops. We also discuss top reconstruction and spin measurement using the variable MT2 and MT2-Assisted On-Shell (MAOS) Momentum} techniques and will also provide a comparison with the on-shell mass relation method. Sensitivities to the flavor-changing top coupling has also been estimated for different LHC energies and projected LHC luminosities corresponding to them.