Search for CP violation in the decays D+ → KSπ+ and D+ → KSK+

A high-statistics sample of photoproduced charm from the FOCUS experiment has been used to search for direct CP violation in the decay rates for D → K S π + and D + → K S K + . We have measured the following asymmetry parameters relative to D + → K - π + π + : A C P (K S π + ) = (-1.6 ′ 1.5 ′ 0.9)%, A C P (K S K + ) = (+6.9 ′ 6.0 ′ 1.5)%, and A C P (K S K + ) = (+7.1 ′ 6.1 ′ 1.2)% relative to D + → K S π + . We have also measured the relative branching ratios and found Γ(D + + K 0 π + )/Γ(D + → K π + π + ) = (30.60 ′ 0.46 ′ 0.32)%, Γ(D + → K 0 K + )/Γ(D + → K - π + π + ) = (6.04 ′ 0.35 ′ 0.30)%, and Γ(D + → K 0 K + )/Γ(D + → K 0 π + ) = (19.96 ′ 1.19 ′ 0.96)%.