  The recent observation of the same-sign dimuon charge asymmetry in the B
system by the D0 collaboration has 3.9 sigma deviation from the standard model
prediction. However, the recent LHCb data on B-s neutral-meson mixing do not
accommodate the D0 collaboration result. In this paper, considering the effect
of Z'-mediated flavour-changing neutral currents in the $ B_q^0 - bar B_q^0$ (q
= d, s) mixing, the same-sign dimuon charge asymmetry is calculated. We find
the same-sign dimuon charge asymmetry is enhanced from its SM prediction and
provides signals for new physics beyond the SM
