A theoretical reappraisal of branching ratios and CP asymmetries in the decays and determination of the CKM parameters
1 Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
2 INFN, Laboratori Nazionali di Frascati, I-00044 Frascati, Italy
Received: 30 December 1998 / Published online: 27 April 1999
We present a theoretical reappraisal of the branching ratios and CP asymmetries for the decays , with q=d,s, taking into account current theoretical uncertainties in the description of the inclusive decay amplitudes from the long-distance contributions, an improved treatment of the renormalization scale dependence, and other parametric dependencies. Concentrating on the partial branching ratios , integrated over the invariant dilepton mass region , we calculate theoretical precision on the charge-conjugate averaged partial branching ratios ,CP asymmetries in partial decay rates , and the ratio of the branching ratios . For the central values of the CKM parameters, we find ,,, , and .The dependence of and on the CKM parameters is worked out and the resulting constraints on the unitarity triangle from an eventual measurement of are illustrated.