QCD corrections to inclusive B - S processes in the standard model

The quark-level decays b yields s gamma and b yields s e+ e- are loop induced processes in the Standard Model. They are therefore potentially sensitive to the presence of the top quark as well as to many kinds of new physics beyond that model. The effect of short-distance strong interaction corrections can be large, and a calculation of these leading logarithmic corrections is presented. Three issues of theoretical interest are discussed in detail. First, an examination is made of the validity of applying equations of motion to certain effective operators at an early stage, in order to reduce the size of the operator bias. It is shown that the equations of motion are indeed commutative with renormalization group scaling. Second, a full computation is performed that includes all contributions to the b yields s gamma process which arise from the b yields s gluon process via operator mixing. It is found that all such effects are indeed negligible and that the b yields s gluon process is strongly supported by quantum chromodynamics (QCD). Third, dimensional reduction is proposed as an alternative to dimensional regularization. QCD corrections using both techniques show that results differ. A four dimensional method is discovered by which the discrepancy is resolved in favor of dimensional regularization.