Lessons from CLEO and FOCUS Measurements of D0-anti-D0 Mixing Parameters

Abstract

If the true values of the D0-anti-D0 mixing parameters lie within the one sigma ranges of recent measurements, then there is strong evidence for a large width difference, y > 0.01, and large SU(3) breaking effects in strong phases, \delta > pi/4. These constraints are model independent, and would become stronger if M_{12}/Gamma_{12} << 1 in the D0-anti-D0 system. The interesting fact that the FOCUS result cannot be explained by a large mass difference is not trivial and depends on the small D0-anti-D0 production asymmetry in FOCUS and the bounds on CP violating effects from CLEO. The large value of \delta might help explain why y ~ sin^2(theta_c).