Alternative technique for standard model estimation of the rare kaon decay branchings BR(K→πν(ν)over-bar)|SM

We estimate BR(K --> piv (v) over bar) in the context of the Standard Model by fitting for lambda(t) equivalent to VtdVts* of the kaon unitarity triangle relation. To find the vertex of this triangle, we fit data from \epsilonK\, the CP-violating parameter describing K mixing, and apsi(K), the CP-violating asymmetry in B-d(0) --> J/psiK(0) decays, and obtain the values BP,(K+ --> pi(+)v (v) over bar)(SM) = (7.07 +/- 1.03) x 10(-11) and BR(K-L(0) --> pi(0)v (v) over bar)\(SM) = L (2.60 +/- 0.52) x 10(-11). Our estimate is independent of the CKM matrix element V-cb and of the ratio of B-mixing frequencies Deltam(Bs)/DeltaM(Bd). We also use the constraint estimation of lambda(t) with additional data from Deltam(Bd) and \V-ub\. This combined analysis slightly increases the precision of the rate estimation of K+ --> pi(+)v (v) over bar and K-L(0) --> pi(0)v (v) over bar (by similar or equal to10and similar or equal to20%, respectively). The measured value of BR(K+ --> pi(+)v (v) over bar) L can be compared both to this estimate and to predictions made from Deltam(Bs)/Deltam(Bd). (C) 2004 MAIK Nauka/Interperiodica.