New Physics Contributions to the Lifetime Difference inD0−D¯0Mixing

We present the first general analysis of New Physics contributions to the $D^0\mathrm{\text{−}}{\overline{D}}^0$ lifetime difference (equivalently $\Delta {\Gamma }_D$). We argue that New Physics (NP) contributions to $|\Delta C|=1$ processes can dominate the lifetime difference in the flavor $SU(3)$ limit. We provide several specific examples of models that produce sizable effects in $\Delta {\Gamma }_D$ for realistic values of light quark masses, even if such NP contributions are undetectable in the current round of $D^0$ decay experiments. This makes $\Delta {\Gamma }_D$ a viable observable for studies of indirect effects of New Physics.