Impact of tag-side interference on time-dependent CP asymmetry measurements using coherent B 0 B 0 pairs

Interference between CKM-favored b {yields} c{bar u}d and doubly-CKM-suppressed {bar b} {yields} {bar u}c{bar d} amplitudes in final states used for B flavor tagging gives deviations from the standard time evolution assumed in CP-violation measurements at B factories producing coherent B{sup 0}{bar B}{sup 0} pairs. We evaluate these deviations for the standard time-dependent CP-violation measurements, the uncertainties they introduce in the measured quantities, and give suggestions for minimizing them. The uncertainty in the measured CP asymmetry for CP eigenstates is {approx} 2% or less. The time-dependent analysis of D*{pi}, proposed for measuring sin(2{beta} + {gamma}), must incorporate possible tag-side interference, which could produce asymmetries as large signal asymmetry.