WEI-SHU HOU2019-12-272019-12-27198503702693https://scholars.lib.ntu.edu.tw/handle/123456789/442879https://www.scopus.com/inward/record.uri?eid=2-s2.0-0001106520&doi=10.1016%2f0370-2693%2887%2990135-3&partnerID=40&md5=303d24412266e6ff3e14a0e5567c25acThe effects of a fourth family on the decays b→s(d)γ are reported. The BR(b→sγ) can become ∼10-3, i.e., a gain from the three-generation result by an order of magnitude. For very massive t′ (mt > 200GeV) the four-generation result is not sensitive to mt, making the reaction usuful for probing the new mixing angles of the fourth generation. We emphasize that combined information from b→sγ, sℓ+ℓ- and the hadronic b→s transition without charmed particles would be useful for constraining mass scales and mixing parameters of a fourth generation. In view of the importance of B decays we present a new parametrization of the 4×4 mixing matrix that appears to be better suited for the study of B physics. © 1987.journal article10.1016/0370-2693(87)90135-32-s2.0-0001106520WOS:A1987J343100036https://www.scopus.com/inward/record.uri?eid=2-s2.0-0001106520&doi=10.1016%2f0370-2693%2887%2990135-3&partnerID=40&md5=303d24412266e6ff3e14a0e5567c25ac