Top-Quark Pairs at High Invariant Mass: A Model-Independent Discriminator of New Physics at the Large Hadron Collider

We study top-quark pair production to probe new physics at the CERN Large Hadron Collider. We propose reconstruction methods for tt semileptonic events and use them to reconstruct the tt invariant mass. The angular distribution of top quarks in their c.m. frame can determine the spin and production subprocess for each new physics resonance. Forward-backward asymmetry and CP-odd variables can be constructed to further delineate the nature of new physics. We parametrize the new resonances with a few generic parameters and show high invariant mass top pair production may provide an early indicator for new physics beyond the standard model