− φ MIXING AND WEAK ANNIHILATION IN D s DECAYS

The mixing between nonstrange and strange quark wavefunctions in the ω and φ mesons leads to a small predicted branching ratio B(D+ s → ωeνe) = O(10−4)(δ/3.34◦)2, where δ is the mixing angle. The value δ = −3.34◦ is obtained in a mass-independent analysis, while a mass-dependent analysis gives δ = −0.45◦ at m(ω) and −4.64◦ at m(φ). Measurement of this branching ratio thus can tell whether the decay is dominated by φ–ω mixing, or additional nonperturbative processes commonly known as “weak annihilation” (WA) contribute. The role of WA in the decay D s → ωπ and its possible use in estimating WA effects in D s → ωeνe are also discussed. Assuming that the dynamics of WA in D s → ωπ is similar in D s → ωeνe we estimate B(D+ s → ωeνe) = (1.3± 0.5)× 10.