Recently, the DØ Collaboration measured the CP-violating like-sign dimuon charge asymmetry in neutral B decays, finding a 3.2ν difference from the standard-model (SM) prediction. A non-SMcharge asymmetry as s1 suggests a new-physics (NP) contribution to Bs-Bs mixing. In this case, in order to explain the measured value of as s1 within its 1s range, NP must be present in Γss 12, the absorptive part of the mixing. In this paper, we examine whether such an explanation is possible in models with flavor-changing Z″ (ZFCNC) or Z″ (Z″FCNC) gauge bosons. The models must also reproduce the measured values of the indirect CP asymmetry Sψφ in Bs → J/ψφ, and δΓs, the Bs-Bs width difference. We find that the ZFCNC model cannot reproduce the present measured values of Sψφ and as s1 within their 1s ranges. On the other hand, in the Z″FCNC model, the values of all three observables can be simultaneously reproduced. © SISSA 2011.