  Entanglement between the spins of top-quark pairs produced at a collider can
be used to test a (generalized) Bell inequality at energies never explored so
far. We show how the measurement of a single observable can provide a test of
the violation of the Bell inequality at the 98% CL with the data already
collected at the Large Hadron Collider and at the 99.99% CL with the higher
luminosity of the next run.
