A fourth chiral generation, with mt′ in the range ∼(300−500) GeV and a moderate value of the CP-violating phase can explain the
anomalous like-sign dimuon charge asymmetry observed recently by the D0
collaboration. The required parameters are found to be consistent with
constraints from other B and K decays. The presence of such quarks, apart
from being detectable in the early stages of the LHC, would also have important
consequences in the electroweak symmetry breaking sector.Comment: 18 pages, 9 figures, Figure 1 is modified, more discussions are added
in section 2. new references adde