Fourth generation effects on the rare B → K ∗ ν¯ν decay

If the fourth generation fermions exist, the new quarks could influence the branching ratio of the rare B → K * ν ¯ ν decay. Two possible solutions of the fourth generation CKM factor (V * ´ ts V ´ tb) (±) are obtained as a function of the new´t-quark mass (m ´ t) from the experimental results of the B → X s γ together with the semileptonic decay B → X c ℓ¯ ν. The branching ratio of the decay B → K * ν ¯ ν in the two cases is estimated. In one case, a significant enhancement to the branching ratio of the decay B → K * ν ¯ ν over the SM is recorded, while results are almost same in another case. If a fourth generation should exist in nature and nature chooses the former case, this B meson decay could be a good probe to the existence of the fourth generation, or perhaps a signal for a new physics.