Calculations of penguin diagrams in B decays
Abstract
We analyze the effects of the space-like penguin diagrams in two body B decays
B
−
→
K
−
K
¯
0
and
B
−
→
π
−
K
¯
0
. Special attention is paid to the operator
Q
6
, whose contribution is large in the BSW model, but vanishes in the PQCD method in the approximation of neglecting the masses in the final states. Suppressions of the space-like penguin diagrams are found in the PQCD method, which implies that the contributions of the space-like penguins are small compared to those of the time-like penguins.