A lower bound on vertical strokeepsilon'/epsilonvertical stroke

In the Kobayashi-Maskawa(K-M) model, a lower bound on the CP violating product s2c2s3ssub(delta) follows from the imaginary part of the short-distance K0-anti K0 mixing amplitude together with a conservative upper bound on the short-distance contribution to Ksub(L) -> μμ. This leads to a lower bound on vertical strokeepsilon'/epsilonvertical stroke in terms of a matrix element of a single (V - A) x (V + A) type operator. Familiar current algebra and bag model estimates for this matrix element give vertical strokeepsilon'/epsilon > 2 x 10-3. We also observe that the experimental upper bound on the branching ratio for the b-quark into u-quarks fixes the sign of s2c2s3ssub(delta) and epsilon'/epsilon both to be positive. Allowances for QCD corrections and long distance effects are included throughout our analysis. (orig.)