Spontaneous CP violation and the B0 system

We investigate the effects of spontaneous breakdown of CP in B0d,s-B0d,s systems in left-right symmetric models. Assuming that the left-right contribution to the B0-B0 matrix element M12 can be at most equal to the standard model one we obtain a new lower bound, MH>or∼12 TeV, on the flavour-changing Higgs boson mass. Most importantly, the convention independent parameter Re(εB), which measures the amount of ΔB=2 CP violation, can be enhanced by a factor of four or more for B0d and almost by two orders of magnitude for B0s systems when compared with the Standard Model predictions. Therefore, interesting possibilities to observe indirect CP violation in the B system are open in the planned facilities. (orig.)