A Time-independent Way to Probe D^0-\bar D^0 Mixing at Tau-charm Factories

Abstract

$D^0-{\bar{D}}^0$ mixing leads to the mass and width differences in the mass eigenstates of $D^0$ and ${\bar{D}}^0$ mesons (measured by parameters $x_D^{}$ and $y_D^{}$ respectively), but their magnitudes cannot be reliably predicted by the standard model. We show that it is possible to separately determine $x_D^{}$ and $y_D^{}$ through {\it time-integrated} measurements of the dilepton events of coherent $D^0{\bar{D}}^0$ decays on the $\psi (4.14)$ resonance at a $\tau$-charm factory.

Comments: 7 pages. Minor changes. (Phys. Lett. B in press)