Measurement of indirect CP asymmetries in D 0 → K − K + and D 0 → π − π + decays using semileptonic B decays

Time-dependent CP asymmetries in the decay rates of the singly Cabibbo-suppressed decays D 0 → K − K + and D 0 → π − π + are measured in pp collision data corresponding to an integrated luminosity of 3.0 fb −1 collected by the LHCb experiment. The D 0 mesons are produced in semileptonic b -hadron decays, where the charge of the accompanying muon is used to determine the initial state as D 0 or D ¯ 0 . The asymmetries in effective lifetimes between D 0 and D ¯ 0 decays, which are sensitive to indirect CP violation, are determined to be