  The tiny neutrino masses can be explained naturally by extending the standard
model with right-handed Majorana neutrinos in low-scale seesaw mechanism, and
the CP violation effect induced by Majorana phase is interesting and worth
studying at colliders. In this paper, we investigate the prospects for
measuring CP violation in top quark pair production and rare decay via Majorana
neutrinos at the LHC. The CP asymmetry stems from the significant interference
of contributions from two different Majorana neutrinos and can be appreciable
when the two neutrino masses are nearly-degenerate. It is found that in the
Majorana neutrino mass range of 10 GeV < mn < 80 GeV, the CP asymmetry is
independent of the Majorana neutrino mass at the LHC. Any possible new
observation of CP violation will be the clear evidence of new physics beyond
the standard model.
