  Simplified models provide an avenue for characterising and exploring New
Physics for large classes of UV theories. In this article we study the ability
of the LHC to probe the spin and parity quantum numbers of a new light
resonance $X$ which couples predominantly to the third generation quarks in a
variety of simplified models through the $t\bar t X$ channel. After evaluating
the LHC discovery potential for $X$, we suggest several kinematic variables
sensitive to the spin and CP properties of the new resonance. We show how an
analysis exploiting differential distributions in the semi-leptonic channel can
discriminate among various possibilities. We find that the potential to
discriminate a scalar from a pseudoscalar or (axial) vector to be particularly
promising.
