Charm mixing as input for model-independent determinations of the CKM phase gamma

The coherence factor and average strong phase difference of D0 and D0bar decay amplitudes to the same final state play an important role in the precision determination of the CKM parameter gamma using B- -> DK- and related decay modes. So far, this important input from the charm sector could only be obtained from measurements based on quantum-correlated DDbar pairs produced at the charm threshold. We propose to constrain these parameters using charm mixing, using the large charm samples available at the B factories and LHCb. We demonstrate for the example of D0->Kpipipi that a substantial improvement in the precision of the coherence factor and average strong phase difference can be obtained with this method, using existing data.