Measurement of CP asymmetries in D^±→η^'π^± and D_s^±→η^'π^± decays

A search for CP violation in D^±→η^'π^± and D^±_s→η^'π^± decays is performed using proton-proton collision data, corresponding to an integrated luminosity of 3 fb^-1, recorded by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The measured CP-violating charge asymmetries are A_CP(D^±→η^'π^±)=(-0.61± 0.72 ± 0.53 ± 0.12)% and A_CP(D^±_s→η^'π^±)=(-0.82± 0.36 ± 0.22 ± 0.27)%, where the first uncertainties are statistical, the second systematic, and the third are the uncertainties on the A_CP(D^±→ K^0_S π^±) and A_CP(D^±_s→ϕπ^±) measurements used for calibration. The results represent the most precise measurements of these asymmetries to date.