Searching for $D^0\bar{D^0}$ mixing

Based on the world's largest near threshold data taken with the BESIII detector at the center of mass energy 3.773 GeV, We implement a method on searching for the $D^0\bar{D^0}$ mixing using quantum coherence between pair-produced $D^0\bar{D^0}$ in $\Psi(3770)$ decays. In this method, the doubly tagged $D^0\bar{D^0}$ events, where the $D^0\bar{D^0}$ mesons has the Quantum Coherence, are used to reconstruct the signals, which makes the biggest background in the experiment, Doubly Cabibbo Suppressed Decay process, cancel out.