出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We report on preliminary results of searches for penguin mediated B decays
based on 20.7 fb−1 of data collected at the (4S) peak with the BaBar detector at PEPII.
The following branching fractions have been measured: B(B+ ! K+) = (7:7+1:6
−1:4
0:8) 10−6, B(B0 ! K0) = (8:1+3:1
−2:5
0:8) 10−6, B(B+ ! K+) = (9:7+4:2
−3:4
1:7)
10−6, B(B0 ! K0) = (8:7+2:5
−2:1
1:1) 10−6, B(B+ ! !+) = (6:6+2:1
−1:8
0:7) 10−6,
B(B ! K0) = (19:8+6:5
−5:6
1:7)10−6, where the rst error is statistical and the second
systematic. For several other modes we report upper limits on their branching fractions;
for example for the following flavor-changing neutral current decays, B(B ! Kl+l−) <
0:6 10−6, B(B ! Kl+l−) < 2:5 10−6, at 90% Con dence Level (C.L.).
