Abstract :
If the fourth generation fermions exist, the new quarks could influence the branching ratio of the decay Bs→νν̄γ. We obtain two solutions of the fourth generation CKM factor V∗t′sVt′b from the decay of B→Xsγ. With these two solutions we calculate the new contributions of the fourth generation quark to Wilson coefficients of the decay Bs→νν̄γ. The branching ratio of the decay Bs→νν̄γ in the two cases are calculated. In one case, our results are quite different from that of SM, but almost same in another case. If a fourth generation should exist in nature and nature chooses the former case, this B meson decay could provide a possible test of the fourth generation existence.
