QCD induced charmless B decays

A detailed discussion of standard model expectations for QCD induced charmless B decays is presented. The loop induced bsg coupling leads to b → sg* transitions where g* could be light-like (on-shell), time-like or space-like (off-shell). New features that are absent in the kaon system emerge, and basically there are four types of subprocesses: b → sg, b → sqanti q, b → sgg and a non-spectator decay of banti q → santi q. We calculate these amplitudes at the parton level and give differential rates relevant for the leading kaon spectrum, as well as laying down the foundation for future simulation work. Exclusive modes are not studied, but we emphasize that b → sg and b → sgg modes have not been adequately taken into account in the literature. We take the incoherent sum over these parton level subprocesses as the inclusive rate for QCD induced charmless B decays (B → K+X). With three generations the inclusive branching ratio is expected at the 1-2% level, and is dominated by b → sqanti q and b → sgg. The existence of a 4th generation has little impact on this prediction, but it may reveal itself in these processes through CP violating effects. Although we do not calculate QCD corrections, their potential effects are discussed. The basic signatur for large QCD corrections is a greatly enhanced b → sg subprocess, but the total rate is not expected to be influenced by too much. Possible enhancements due to physics beyond the standard model is briefly discussed. Experimental techniques to handle this decay mode at future 'B factories' is urged. (orig.)