Fourth-generation effects on the rare B→K*νν-bar decay

The rare B→K*νν-bar decay is analysed with a new up-like quark t-' in a sequential fourth-generation model. Two possible solutions for the fourth-generation CKM (Cabibbo-Kabayashi-Maskawa) factor Vts*Vtb± obtained as a function of the new t-' quark mass are used. The branching ratio (BR) and missing-energy spectrum of this decay in the two cases are estimated. In one case, it is shown that for mt-'≥ 200 GeV a significant enhancement to the BR and the missing-energy spectrum of this decay over the SM (standard model) is recorded, while the results are almost same in the other case. If a fourth generation should exist in nature and nature chooses this case, this B-meson decay mode could be a good probe for the existence of the fourth generation, or perhaps a signal for a new physics. (author)