Indirect $\\boldsymbol{CP}$ Violation in $\\boldsymbol{D^0 \\rightarrow h^+\n h^-}$ Decays at LHCb

Indirect CP violation in the $D^0$ system can be probed by measuring the\nparameter $A_{\\Gamma}$, defined as the CP asymmetry of the effective lifetime\nof the $D^0$ meson decaying to a CP eigenstate. This can be significantly\nenhanced beyond Standard Model predictions by new physics. Measurements of\n$A_{\\Gamma}$ using $D^0 \\rightarrow K^+K^-$ and $D^0\\rightarrow \\pi^+\\pi^-$\ndecays reconstructed from pp collisions collected by the LHCb experiment,\ncorresponding to an integrated luminosity of 1.0 fb$^{-1}$, are presented. The\nresults are \\begin{align*}\n A_{\\Gamma} (\\pi\\pi) = (+0.33 \\pm 1.06 \\pm 0.14) \\times 10^{-3},\\quad\n A_{\\Gamma} (KK) = (-0.35 \\pm 0.62 \\pm 0.12) \\times 10^{-3}, \\end{align*}\nwhere the uncertainties are statistical and systematic, respectively. These are\nthe most precise measurements of their kind to date, and show no evidence of CP\nviolation.\n